Method of treatment using substituted pyrazolo[1,5-a]pyrimidine compounds

ABSTRACT

Compounds useful in the synthesis of compounds for treating pain, cancer, inflammation, neurodegenerative disease or  Typanosoma cruzi  infection in a mammal.

This application is a divisional of U.S. Ser. No. 13/125,263 filed Apr.20, 2011, which is a Section 371(e) filing from PCT/US09/061,519, filedOct. 21, 2009, which claims the benefit of U.S. provisional patentapplication No. 61/107,616 filed Oct. 22, 2008, each of which isincorporated herein in its entirety.

The present invention relates to novel compounds, to pharmaceuticalcompositions comprising the compounds, to a process for making thecompounds and to the use of the compounds in therapy. More particularly,it relates to certain substituted pyrazolo[1,5-a]pyrimidine compoundswhich exhibit Trk family protein tyrosine kinase inhibition, and whichare useful in the treatment of pain, inflammation, cancer, and certaininfectious diseases.

The current treatment regimes for pain conditions utilize severalclasses of compounds. The opioids (such as morphine) have severaldrawbacks including emetic, constipatory and negative respiratoryeffects, as well as the potential for addictions. Non-steroidalanti-inflammatory analgesics (NSAIDs, such as COX-1 or COX-2 types) alsohave drawbacks including insufficient efficacy in treating severe pain.In addition, COX-1 inhibitors can cause ulcers of the mucosa.Accordingly, there is a continuing need for new and more effectivetreatments for the relief of pain, especially chronic pain.

Trk's are the high affinity receptor tyrosine kinases activated by agroup of soluble growth factors called neurotrophins (NT). The Trkreceptor family has three members—TrkA, TrkB and TrkC. Among theneurotrophins are (i) nerve growth factor (NGF) which activates TrkA,(ii) brain-derived neurotrophic factor (BDNF) and NT-4/5 which activateTrkB and (iii) NT3 which activates TrkC. Trk's are widely expressed inneuronal tissue and are implicated in the maintenance, signaling andsurvival of neuronal cells (Patapoutian, A. et al., Current Opinion inNeurobiology, 2001, 11, 272-280).

Inhibitors of the Trk/neurotrophin pathway have been demonstrated to beeffective in numerous pre-clinical animal models of pain. For example,antagonistic NGF and TrkA antibodies (for example, RN-624) have beenshown to be efficacious in inflammatory and neuropathic pain animalmodels and in human clinical trials (Woolf, C. J. et al. (1994)Neuroscience 62, 327-331; Zahn, P. K. et al. (2004) J. Pain 5, 157-163;McMahon, S. B. et al., (1995) Nat. Med. 1, 774-780; Ma, Q. P. and Woolf,C. J. (1997) Neuroreport 8, 807-810; Shelton, D. L. et al. (2005) Pain116, 8-16; Delafoy, L. et al. (2003) Pain 105, 489-497; Lamb, K. et al.(2003) Neurogastroenterol. Motil. 15, 355-361; Jaggar, S. I. et al.(1999) Br. J. Anaesth. 83, 442-448). Additionally, recent literatureindicates after inflammation, BDNF levels and TrkB signaling isincreased in the dorsal root ganglion (Cho, L. et al. Brain Research1997, 749, 358) and several studies have show antibodies that decreasesignaling through the BDNF/TrkB pathway inhibit neuronalhypersensitization and the associated pain (Chang-Qi, L et al. MolecularPain 2008, 4:27).

In addition, it has been shown that tumor cell sand tumor invadingmacrophages directly stimulates TrkA located on peripheral pain fibers.Using various tumor models in both mice and rats it was demonstratedthat neutralizing NGF with a monoclonal antibody inhibits cancer relatedpain to a degree similar or superior to the highest tolerated dose ofmorphine. In addition, activation of the BDNF/TrkB pathway has beenimplicated in numerous studies as a modulator of various types of painincluding inflammatory pain (Matayoshi, S., J. Physiol. 2005,569:685-95), neuropathic pain (Thompson, S. W., Proc. Natl. Acad. Sci.USA 1999, 96:7714-18) and surgical pain (Li, C.-Q. et al., MolecularPain, 2008, 4(28), 1-11). Because TrkA and TrkB kinases may serve as amediator of NGF driven biological responses, inhibitors of TrkA and/orother Trk kinases may provide an effective treatment for chronic painstates.

Recent literature has also shown that overexpression, activation,amplification and/or mutation of Trk's are associated with many cancersincluding neuroblastoma (Brodeur, G. M., Nat. Rev. Cancer 2003, 3,203-216), ovarian cancer (Davidson. B., et al., Clin. Cancer Res. 2003,9, 2248-2259), breast cancer (Kruettgen et al, Brain Pathology 2006, 16:304-310), prostate cancer (Dionne et al, Clin. Cancer Res. 1998, 4(8):1887-1898), pancreatic cancer (Dang et al, Journal of Gastroenterologyand Hepatology 2006, 21(5): 850-858), multiple myeloma (Hu et al, CancerGenetics and Cytogenetics 2007, 178: 1-10), astrocytoma andmedulloblastoma (Kruettgen et al, Brain Pathology 2006, 16: 304-310)glioma (Hansen et al, Journal of Neurochemistry 2007, 103: 259-275),melanoma (Truzzi et al, Journal of Investigative Dermatology 2008,128(8): 2031-2040, thyroid carcinoma (Brzezianska et al,Neuroendocrinology Letters 2007, 28(3), 221-229), lung adenocarcinoma(Perez-Pinera et al, Molecular and Cellular Biochemistry 2007, 295(1&2),19-26), large cell neuroendocrine tumors (Marchetti et al, HumanMutation 2008, 29(5), 609-616), and colorectal cancer (Bardelli, A.,Science 2003, 300, 949). In preclinical models of cancer, Trk inhibitorsare efficacious in both inhibiting tumor growth and stopping tumormetastasis. In particular, non-selective small molecule inhibitors ofTrk A, B and C and Trk/Fc chimeras were efficacious in both inhibitingtumor growth and stopping tumor metastasis (Nakagawara, A. (2001) CancerLetters 169:107-114; Meyer, J. et al. (2007) Leukemia, 1-10; Pierottia,M. A. and Greco A., (2006) Cancer Letters 232:90-98; Eric Adriaenssens,E. et al. Cancer Res (2008) 68:(2) 346-351) (Truzzi et al, Journal ofInvestigative Dermatology 2008, 128(8): 2031-2040. Therefore, aninhibitor of the Trk family of kinases is expected to have utility inthe treatment of cancer.

In addition, inhibition of the neurotrophin/Trk pathway has been shownto be effective in treatment of pre-clinical models of inflammatorydiseases. For example, inhibition of the neurotrophin/Trk pathway hasbeen implicated in preclinical models of inflammatory lung diseasesincluding asthma (Freund-Michel, V; Frossard, N.; Pharmacology &Therapeutics (2008), 117(1), 52-76), interstitial cystitis (Hu Vivian Y;et. al. The Journal of Urology (2005), 173(3), 1016-21), inflammatorybowel diseases including ulcerative colitis and Crohn's disease (DiMola, F. F, et. al., Gut (2000), 46(5), 670-678) and inflammatory skindiseases such as atopic dermatitis (Dou, Y.-C.; et. al. Archives ofDermatological Research (2006), 298(1), 31-37), eczema and psoriasis(Raychaudhuri, S. P.; et. al. Journal of Investigative Dermatology(2004), 122(3), 812-819).

The neurotrophin/Trk pathway, particularly BDNF/TrkB, has also beenimplicated in the etiology of neurodegenerative diseases includingmultiple sclerosis, Parkinson's disease and Alzheimer's disease(Sohrabji, Farida; Lewis, Danielle K. Frontiers in Neuroendocrinology(2006), 27(4), 404-414). Modulation of the neutrophin/Trk pathway mayhave utility in treatment of these and related diseases.

The TrkA receptor is also thought to be critical to the disease processin the infection of the parasitic infection of Typanosoma cruzi (Chagasdisease) in human hosts (de Melo-Jorge, M. et al. Cell Host & Microbe(2007), 1(4), 251-261). Thus, TrkA inhibition my have utility intreating Chagas disease and related protozoan infections.

Trk inhibitors may also find use in treating disease related to animbalance of the requlation of bone remodeling, such as osteoporosis,rheumatoid arthritis, and bone metastases. Bone metastases are afrequent complication of cancer, occurring in up to 70 percent ofpatients with advanced breast or prostate cancer (1) and inapproximately 15 to 30 percent of patients with carcinoma of the lung,colon, stomach, bladder, uterus, rectum, thyroid, or kidney. Osteolyticmetastases can cause severe pain, pathologic fractures, life-threateninghypercalcemia, spinal cord compression, and other nerve-compressionsyndromes. For these reasons, bone metastasis is a serious and costlycomplication of cancer. Therefore, agents that can induce apoptosis ofproliferating osteoblasts would be highly advantageous. Expression ofTrkA and TrkC receptors has been observed in the bone forming area inmouse models of bone fracture (K. Asaumi, et al., Bone (2000) 26(6)625-633). In addition, localization of NGF was observed in almost allbone forming cells (K. Asaumi, et al.). Recently, it was demonstratedthat a pan-Trk inhibitor inhibits the tyrosine signaling activated byneurotrophins binding to all three of the Trk receptors in human hFOBosteoblasts (J. Pinski, et al., (2002) 62, 986-989). These data supportthe rationale for the use of Trk inhibitors for the treatment of boneremodeling diseases, such as bone metastases in cancer patients.

Several classes of small molecule inhibitors of Trk kinases said to beuseful for treating pain or cancer are known (Expert Opin. Ther. Patents(2009) 19(3)).

International Patent Application Publications WO 2006/115452 and WO2006/087538 describe several classes of small molecules said to beinhibitors or Trk kinases which could be useful for treating pain orcancer.

Pyrazolo[1,5-a]pyrimidine compounds are known. For example,International Patent Application Publication WO 2008/037477 disclosespyrazolo[1,5-a]pyrimidine compounds bearing an alkyl, aryl orheterocyclic group at the 3-position. These compounds are asserted to bePI3K and/or mTOR Lipid Kinase inhibitors.

International Patent Application Publication WO 2008/058126 disclosespyrazolo[1,5-a]pyrimidine compounds bearing a phenyl group at the3-position. These compounds are asserted to be Pim-kinase inhibitors.

U.S. Publication US 2006/0094699 discloses pyrazolo[1,5-a]pyrimidinecompounds bearing a —C(═O)NH-phenyl, —C(═O)(4-methylpiperidinyl) or—C(═O)NMe(CH₂-trimethylpyrazolyl) group at the 3-position for use incombination therapy with a glucocorticoid receptor agonist.

It has now been found that certain pyrazolo[1,5-a]pyrimidine compoundsbearing an aryl or heteroaryl-substituted heterocyclic group at the5-position and a group having the formula NR¹C(═O)R² at the 3-position,wherein R¹ and R² are as defined herein, are inhibitors of Trk kinases,in particular inhibitors of TrkA and/or TrkB, which are useful fortreating disorders and diseases which can be treated by inhibiting TrkAand/or TrkB kinases, such as pain, including chronic and acute pain, orcancer. Certain compounds which are dual inhibitors of TrkA and TrkB maybe useful in the treatment of multiple types of pain includinginflammatory pain, neuropathic pain, surgical pain, and pain associatedwith cancer, surgery and bone fracture. Selectivity for TrkA and/or TrkBis particularly desirable in compounds for use in treating pain. Inaddition, compounds of the invention may be useful for treating cancer,inflammation, neurodegenerative diseases and certain infectiousdiseases.

Accordingly, one embodiment of this invention provides a compound of thegeneral Formula I:

or a pharmaceutically acceptable salt thereof, wherein:

R¹ is H or (1-6C alkyl);

R² is NR^(b)R^(c), (1-4C)alkyl, (1-4C)fluoroalkyl, CF₃,(1-4C)hydroxyalkyl, -(1-4C alkyl)hetAr¹, -(1-4C alkyl)NH₂, -(1-4Calkyl)NH(1-4C alkyl), -(1-4C alkyl)N(1-4C alkyl)₂, hetAr², hetCyc¹,hetCyc², phenyl which is optionally substituted with NHSO₂(1-4C alkyl),or (3-6C)^(e)cycloalkyl which is optionally substituted with (1-4Calkyl), CN, OH, OMe, NH₂, NHMe, N(CH₃)₂, F, CF₃, CO₂(1-4C alkyl), CO₂H,C(═O)NR^(e)R^(f) or C(═O)OR^(g);

R^(b) is H or (1-6C alkyl);

R^(c) is H, (1-4C)alkyl, (1-4C)hydroxyalkyl, hetAr³, or phenyl, whereinsaid phenyl is optionally substituted with one or more substituentsindependently selected from halogen, CN, CF₃ and —O(1-4C alkyl),

or NR^(b)R^(c) forms a 4 membered heterocyclic ring having a ringnitrogen atom wherein said heterocyclic ring is optionally substitutedwith one or more substituents independently selected from halogen, OH,(1-4C alkyl), (1-4C)alkoxy, —OC(═O)(1-4C alkyl), NH₂, —NHC(═O)O(1-4Calkyl) and (1-4C)hydroxyalkyl,

or NR^(b)R^(c) forms a 5-6 membered heterocyclic ring having a ringheteroatom which is nitrogen and optionally having a second ringheteroatom or group selected from N, O and SO₂, wherein the heterocyclicring is optionally substituted with one or more substituentsindependently selected from OH, halogen, CF₃, (1-4C)alkyl, CO₂(1-4Calkyl), CO₂H, NH₂, NHC(═O)O(1-4C alkyl) and oxo,

or NR^(b)R^(c) forms a 7-8 membered bridged heterocyclic ring having aring nitrogen atom and optionally having a second ring heteroatomselected from N and O, wherein said ring is optionally substituted withCO₂(1-4C alkyl);

hetAr¹ is a 5-membered heteroaryl ring having 1-3 ring nitrogen atoms;

hetAr² is 5-6 membered heteroaryl ring having at least one nitrogen ringatom and optionally having a second ring heteroatom independentlyselected from N and S, wherein said heteroaryl ring is optionallysubstituted with one or more substituents independently selected from(1-4C alkyl), halogen, -(1-4C)alkoxy, and NH(1-4C alkyl);

hetCyc¹ is a carbon-linked 4-6 membered azacyclic ring optionallysubstituted with one or more substituents independently selected from(1-4C alkyl), and CO₂(1-4C alkyl);

hetCyc² is a pyridinone or pyridazinone ring which is optionallysubstituted with a substituent selected from (1-4C)alkyl;

hetAr³ is a 5-6 membered heteroaryl ring having 1-2 ring heteroatomsindependently selected from N and O and optionally substituted with oneor more substituents independently selected from (1-4C)alkyl;

R^(e) is H or (1-4C)alkyl;

R^(f) is H, (1-4C)alkyl, or (3-6C)cycloalkyl;

or NR^(e)R^(f) forms a 5-6-membered azacyclic ring optionally having anadditional ring heteroatom selected from N and O, wherein the azacyclicring is optionally substituted with OH;

R^(g) is H or (1-6C)alkyl;

Y is (i) phenyl optionally substituted with one or more substituentsindependently selected from halogen, (1-4C)alkoxy, CF₃ and CHF₂, or (ii)a 5-6 membered heteroaryl ring having a ring heteroatom selected from Nand S, wherein said heteroaryl ring is optionally substituted with oneor more halogen atoms;

X is null, —CH₂—, —CH₂CH₂—, —CH₂O— or —CH₂NR^(d)—;

R^(d) is H or (1-4C alkyl);

R³ is H or (1-4C alkyl);

each R⁴ is independently selected from halogen, (1-4C)alkyl, OH,(1-4C)alkoxy, NH₂, NH(1-4C alkyl) and CH₂OH; and

n is 0, 1, 2, 3, 4, 5 or 6.

In certain embodiments of Formula I, R² is selected from any of thevalues described above, other than C(═O)NR^(e)R^(f) or C(═O)OR^(g).

In certain embodiments of Formula I, R¹ is hydrogen.

In certain embodiments of Formula I, R¹ is (1-6C)alkyl. A particularexample is methyl.

In certain embodiments of Formula I, R² is a group having the formulaNR^(b)R^(c), such that the group at the 3 position of thepyrazolo[1,5-a]pyrimidine core of Formula I has the formula—NR¹C(═O)NR^(b)R^(c).

In certain embodiments, R^(b) is H or (1-6C alkyl).

In certain embodiments, R^(b) is H. In certain embodiments, R^(b) is(1-6C alkyl), for example Me.

In certain embodiments, R² is NR^(b)R^(c) where R^(c) is H, (1-4C)alkyl,(1-4C)hydroxyalkyl, hetAr³, or phenyl, wherein said phenyl is optionallysubstituted with one or more substituents independently selected fromhalogen, CN, CF₃ and —O(1-4C alkyl).

In certain embodiments, R² is NR^(b)R^(c), where R^(c) is hydrogen. Inparticular embodiments, the group represented by NR^(b)R^(c) is NH₂.

In certain embodiments, R² is NR^(b)R^(c), where R^(c) is (1-4C)alkyl.Examples include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, andthe like. In particular embodiments, the group represented byNR^(b)R^(c) includes NHMe, NMe₂ and NH(t-butyl).

In certain embodiments, R² is NR^(b)R^(c), where R^(c) is(1-4C)hydroxyalkyl. Examples include CH₂CH₂OH and CH₂CH₂CH₂OH. Inparticular embodiments, the group represented by NR^(b)R^(c) includesNMe(CH₂CH₂OH).

In certain embodiments, R² is NR^(b)R^(c), where R^(c) is hetAr³, andhetAr³ is an optionally substituted 5-6 membered heteroaryl ring having1-2 ring heteroatoms independently selected from N and O. An example ofhetAr³ includes an isoxazolyl ring. In certain embodiments, hetAr³ isunsubstituted. In other embodiments, hetAr³ is substituted with one ormore substituents independently selected from (1-4C)alkyl, for exampleone or more substituents independently selected from methyl and ethyl.Examples of hetAr³ include dimethylisoxazolyl. In particularembodiments, the group represented by NR^(b)R^(c) includes the grouphaving the structure:

In certain embodiments, R² is NR^(b)R^(c), where R^(c) is a phenyl groupoptionally substituted with one or more substituents independentlyselected from halogen, CN, CF₃ and O-(1-4C alkyl). Examples of R^(c)include phenyl, fluorophenyl, chlorophenyl, cyanophenyl, methoxyphenyl,trifluoromethylphenyl, dichlorophenyl, and trimethoxyphenyl. Moreparticular examples include 4-fluorophenyl, 3-chlorophenyl,4-chlorophenyl, 3-cyanophenyl, 4-cyanophenyl, 4-methoxyphenyl,2-4-dichlorophenyl, 3-(trifluoromethyl)phenyl, 3,5-dichlorophenyl, and3,4,5-trimethoxyphenyl. In particular embodiments, the group representedby NR^(b)R^(c) includes the structures:

In certain embodiments, R² is NR^(b)R^(c), where R^(c) is selected fromH, Me, t-butyl, CH₂CH₂OH and CH₂CH₂CH₂OH, dimethylisoxazolyl, phenyl,fluorophenyl, chlorophenyl, cyanophenyl, methoxyphenyl,trifluoromethylphenyl, dichlorophenyl, and trimethoxyphenyl. Moreparticular examples include 4-fluorophenyl, 3-chlorophenyl,4-chlorophenyl, 3-cyanophenyl, 4-cyanophenyl, 4-methoxyphenyl,2-4-dichlorophenyl, 3-(trifluoromethyl)phenyl, 3,5-dichlorophenyl, and3,4,5-trimethoxyphenyl. In one embodiment, R^(b) is H. In oneembodiments, R^(b) is (1-6C alkyl), for example methyl.

In certain embodiments, R² is —NR^(b)R^(c), wherein:

(i) NR^(b)R^(c) forms a 4 membered heterocyclic ring having a ringnitrogen atom, wherein said ring is optionally substituted with one ormore substituents independently selected from halogen, OH, (1-4C alkyl),(1-4C)alkoxy, —OC(═O)(1-4C alkyl), NH₂, —NHC(═O)O(1-4C alkyl) and(1-4C)hydroxyalkyl, or

(ii) NR^(b)R^(c) forms a 5-6 membered heterocyclic ring having a ringheteroatom which is nitrogen and optionally having a second ringheteroatom or group selected from N, O and SO₂, wherein the heterocyclicring is optionally substituted with one or more substituentsindependently selected from OH, halogen, CF₃, (1-4C)alkyl, CO₂(1-4Calkyl), CO₂H, NH₂, NHC(═O)O(1-4C alkyl) and oxo, or

(iii) NR^(b)R^(c) forms a 7-8 membered bridged heterocyclic ring havinga ring nitrogen atom and optionally having a second ring heteroatomselected from N and O, wherein said ring is optionally substituted withCO₂(1-4C alkyl).

In certain embodiments, R² is —NR^(b)R^(c), wherein —NR^(b)R^(c) forms a4 membered heterocyclic ring having a ring nitrogen atom, wherein saidring is optionally substituted with one or more substituentsindependently selected from halogen, OH, (1-4C alkyl), —O(1-4C alkyl),—OC(═O)(1-4C alkyl), NH₂, —NHC(═O)O(1-4C alkyl) and (1-4C)hydroxyalkyl.Examples include azetidinyl rings optionally substituted with one ormore substituents independently selected from F, OH, methyl, OMe,OC(═O)C(CH₃)₂, NH₂, —NHC(═O)OC(CH₃)₃ and CH₂OH. Particular examples ofR² when represented by —NR^(b)R^(c), wherein —NR^(b)R^(c) forms a 4membered heterocyclic ring, include the structures:

In certain embodiments, R² is —NR^(b)R^(c), wherein —NR^(b)R^(c) forms a4 membered azcyclic ring optionally substituted with one or twosubstituents independently selected from OH, (1-4C alkyl), and —O(1-4Calkyl), for example OH, Me and OMe.

In certain embodiments, R² is —NR^(b)R^(c), wherein —NR^(b)R^(c) forms a5-6 membered heterocyclic ring having a ring heteroatom which isnitrogen and optionally having a second ring heteroatom or groupselected from N, O and SO₂, wherein the heterocyclic ring is optionallysubstituted with one or more substituents independently selected fromOH, halogen, CF₃, (1-4C)alkyl, CO₂(1-4C alkyl), CO₂H, NH₂, NHC(═O)O(1-4Calkyl) and oxo. Examples include optionally substituted pyrrolidinyl,piperidinyl, piperazinyl, morpholinyl and piperidinesulfone rings.Examples of substituents on the 5-6 membered heterocyclic ring includeOH, F, NH₂, CO₂H, CO₂Et, NHCO₂C(CH₃)₃, CF₃, methyl, ethyl, isopropyl,CO₂C(CH₂)₃ and oxo. In one embodiment, the heterocyclic ring isoptionally substituted with one or two of said substituents. Particularexamples of R² when represented by —NR^(b)R^(c), wherein —NR^(b)R^(c)forms a 5-6 membered heterocyclic ring, include the structures:

In certain embodiments, R² is —NR^(b)R^(c), wherein —NR^(b)R^(c) forms a5-membered heterocyclic ring optionally substituted with one or twosubstituents independently selected from OH and (1-4C) alkyl, forexample OH and Me. In certain embodiments, —NR^(b)R^(c) forms anazacyclic ring optionally substituted with one to two substitutedindependently selected from OH and Me.

In certain embodiments, R² is —NR^(b)R^(c), wherein —NR^(b)R^(c) forms a6-membered heterocyclic ring optionally substituted with one or twosubstituents independently selected from OH and (1-4C) alkyl, forexample OH and Me.

In certain embodiments, R² is —NR^(b)R^(c), wherein NR^(b)R^(c) forms a7-8 membered bridged heterocyclic ring having a ring nitrogen atom andoptionally having a second ring heteroatom selected from N and O,wherein said ring is optionally substituted with CO₂(1-4C alkyl).Examples of bridged heterocyclic rings include diazabicyclooctane ringssuch as 3,8-diazabicyclo[3.2.1]octane and oxa-azabicyclo[2.2.1]heptanerings, which are optionally substituted with CO₂(1-4C alkyl), such asCO₂C(CH₃)₃. Particular examples of R² when represented by —NR^(b)R^(c),wherein —NR^(b)R^(c) forms a 7-8 membered bridged heterocyclic ring,include the structures:

In certain embodiments, R² is selected from (1-4C)alkyl,(1-4C)fluoroalkyl, CF₃, -(1-4C)hydroxyalkyl, (1-4C alkyl)hetAr¹, and-(1-4C alkyl)NH(1-4C alkyl).

In certain embodiments, R² is (1-4C)alkyl. Particular examples includemethyl, isopropyl and tert-butyl.

In certain embodiments, R² is (1-4C)fluoroalkyl. A particular exampleincludes CF(CH₃)₂.

In certain embodiments, R² is CF₃.

In certain embodiments, R² is (1-4C)hydroxyalkyl. Particular examplesinclude C(CH₃)₂OH and C(CH₃)₂CH₂OH.

In certain embodiments, R² is -(1-4C alkyl)hetAr¹, where hetAr¹ is a5-membered heteroaryl ring having 1-3 ring nitrogen atoms. An example ofhetAr¹ is a triazolyl ring, such as 1,2,4-triazolyl. Examples of the(1-4C)alkyl portion include methylene, ethylene, dimethylmethylene, andthe like. A particular value for R² when represented by -(1-4Calkyl)hetAr¹ is the structure:

In certain embodiments, R² is -(1-4C alkyl)NH(1-4C alkyl). Examplesinclude groups having the formula (1-4C alkyl)NHCH₃. A particular valueinclude —C(CH₃)₂NHCH₃.

In certain embodiments, R² is selected from methyl, isopropyl,tert-butyl, CF(CH₃)₂, CF₃, C(CH₃)₂OH and C(CH₃)₂CH₂OH,2-(1,2,4-triazolyl)propan-2-yl, and —C(CH₃)₂NHCH₃.

In certain embodiments, R² is (3-6C cycloalkyl) which is optionallysubstituted with (1-4C)alkyl, CN, OH, OMe, NH₂, NHMe, N(CH₃)₂, F, CF₃,CO₂(1-4C alkyl) or CO₂H. In certain embodiments, R² is a cyclopropylring optionally substituted with (1-4C alkyl), CN, OH, CF₃, CO₂(1-4Calkyl) or CO₂H. Particular examples of R² include the structures:

In certain embodiments R² is a (3-6C cycloalkyl) include cyclopropyl,cyclobutyl and cyclopentyl rings optionally substituted with (1-4Calkyl), CN, OH, CF₃, CO₂(1-4C alkyl) or CO₂H. Examples includecyclobutyl and cyclopentyl rings optionally substituted with OH. Furtherexamples of R² include the structures:

In certain embodiments, R² is selected from hCtAr², hetCyc¹, andhetCyc².

In certain embodiments, R² is hetAr². Examples of hetAr² includepyridyl, pyrimidyl, pyrazinyl, pyrazolyl, imidazolyl and thiazolyl ringsoptionally substituted with one or more substituents independentlyselected from (1-4C alkyl), halogen, (1-4C)alkoxy and NH(1-4C alkyl).Particular examples of substituents for hetAr² include methyl, ethyl,chloro, OMe, and NHCH(CH₃)₂. In certain embodiments, hetAr² isoptionally substituted with 1 or 2 of said substituents. Particularvalues of R² when represented by hetAr² include the structures:

In certain embodiments, R² is hetCyc¹. Examples of hetCyc¹ includecarbon-linked azetidinyl, pyrrolidinyl and piperidinyl rings optionallysubstituted with one or more substituents independently selected from(1-4C alkyl), CO₂H and CO₂(1-4C alkyl). Examples of substituents includemethyl, ethyl, propyl, CO₂Me, CO₂Et and CO₂C(CH₃)₃. In one embodiment,hetCyc¹ is optionally substituted with one or two of said substituents.Particular values for R² represented by hetCyc¹ include the structures:

In certain embodiments, R² is hetCyc². Examples include a pyridinone orpyridazinone ring which is optionally substituted with a substituentselected from (1-4C)alkyl such as a methyl or ethyl group. Particularvalues of R² when represented by hetCyc² include the structures:

In certain embodiments, R² is selected from (i) pyridyl, pyrimidyl,pyrazinyl, pyrazolyl, imidazolyl and thiazolyl rings optionallysubstituted with one or more substituents independently selected from(1-4C alkyl), halogen, (1-4C)alkoxy and NH(1-4C alkyl); (ii)carbon-linked azetidinyl, pyrrolidinyl and piperidinyl rings optionallysubstituted with one or more substituents independently selected from(1-4C alkyl), CO₂H and CO₂(1-4C alkyl); and (iii) a pyridinone orpyridazinone ring which is optionally substituted with a substituentselected from (1-4C)alkyl.

In certain embodiments, R² is selected from the structures:

In certain embodiments, R² is phenyl which is optionally substitutedwith an NHSO₂(1-4C alkyl) group such a methanesulfonamido or anethanesulfonamido group. Particular values for R² include thestructures:

In certain embodiments, R² is C(═O)NR^(e)R^(f) or C(═O)OR^(g).

In certain embodiments, R² is C(═O)NR^(e)R^(f). In certain embodiments,R^(e) is H or (1-4C)alkyl and R^(f) is H, (1-4C)alkyl, or(3-6C)cycloalkyl. Particular values for R² include C(═O)NH₂, C(═O)NMe,C(═O)NMe₂ and C(═O)NH-cyclopropyl.

In certain embodiments R² is C(═O)NR^(e)R^(f), where NR^(e)R^(f) forms a4-6-membered azacyclic ring optionally having an additional ringheteroatom selected from N and O, wherein the azacyclic ring isoptionally substituted with OH. Particular values for R² include thestructures:

In certain embodiments where R² is C(═O)OR^(g). Particular examplesinclude C(═O)OH and C(═O)Me.

Referring now to the substituents on the ring at the 5-position ofFormula I, in one embodiment Y is phenyl optionally substituted with oneor more substituents independently selected from halogen, (1-4C)alkoxy,CF₃ and CHF₂. In one embodiment, Y is phenyl optionally substituted withone or more substituents independently selected from F, Cl, OMe, CF₃ andCHF₂. In certain embodiments, Y is phenyl optionally substituted withone or two of said substituents. Particular values for Y include phenyl,3-fluorophenyl, 2,5-difluorophenyl, 2-chloro-5-fluorophenyl,2-methoxyphenyl, 2-methoxy-5-fluorophenyl,2-trifluoromethyl-5-fluorophenyl, 2-difluoromethyl-5-fluorophenyl and3-chloro-5-fluorophenyl.

In one embodiment, Y is a 5-6 membered heteroaryl ring having a ringheteroatom selected from N and S and optionally substituted with one ormore halogen atoms. Examples include pyridyl and thienyl groupsoptionally substituted with one or more halogen atoms, for example oneor more fluoro atoms. Particular values for Y include 2-pyridyl,3-pyridyl, 5-fluoropyrid-3-yl and 2-thienyl.

In one embodiment, the Y group has the absolute configuration shown inFIG. Ia:

With reference to the R³ substituent, in one embodiment R³ is H. In oneembodiment, R³ is (1-4C)alkyl, for example, methyl, ethyl, propyl,isopropyl or butyl. Particular values for R³ include hydrogen andmethyl.

With reference to the R⁴ substituent, in one embodiment R⁴ is halogen.Particular examples are fluoro and chloro.

In one embodiment, R⁴ is (1-4C)alkyl, such as methyl, ethyl, propyl,isopropyl, or butyl. A particular example is methyl.

In one embodiment, R⁴ is OH.

In one embodiment, R⁴ is (1-4C)alkoxy, for example OMe and OEt.

In one embodiment, R⁴ is NH₂.

In one embodiment, R⁴ is NH(1-4C alkyl), for example NHMe, NHEt, NHPr,NHiPr or NHBu. A particular example is NHMe.

In one embodiment, R⁴ is CH₂OH.

In one embodiment, each R⁴ is independently selected from F, Cl, OH,OMe, NH₂, Me, CH₂OH and NHMe.

In one embodiment, n is 0, 1, 2, 3 or 4. In one embodiment, n is 0, 1, 2or 3. In one embodiment, n is 0, 1 or 2.

With continued reference to the ring at the 5-position of Formula I, incertain embodiments, X is null, —CH₂— or —CH₂CH₂—.

In one embodiment X is null, such that the heterocyclic ring at the5-position of Formula I has the structure:

where R³, R⁴, Y and n are as defined herein. In one embodiment, Y isphenyl optionally substituted with one or more substituentsindependently selected from halogen, (1-4C)alkoxy, CF₃ and CHF₂. In oneembodiment, Y is 5-6 membered heteroaryl ring having a ring heteroatomselected from N and S, wherein said heteroaryl ring is optionallysubstituted with one or more halogen atoms. In one embodiment, R³ ishydrogen. In another embodiment, R³ is methyl. A particular example ofthe ring at the 5-position of Formula I when X is null includes thestructures:

In one embodiment, X is CH₂, such that the heterocyclic ring at the5-position of Formula I has the structure:

where R³, R⁴, Y and n are as defined herein. In one embodiment Y isphenyl optionally substituted with one or more substituentsindependently selected from halogen, (1-4C)alkoxy, CF₃ and CHF₂. In oneembodiment, Y is a 5-6 membered heteroaryl ring having a ring heteroatomselected from N and S, wherein said heteroaryl ring is optionallysubstituted with one or more halogen atoms. In one embodiment, R³ ishydrogen. In another embodiment, R³ is methyl. In one embodiment, eachR⁴ is independently selected from F, Cl, Me, OH, OMe, NH₂, NHMe, CH₂OH,CHF₂ and CF₃. In one embodiment, n is 0, 1 or 2. Particular examples ofthe ring at the 5-position of Formula I when X is CH₂ include thestructures:

In one embodiment, X is CH₂CH₂, such that the heterocyclic ring at the5-position of Formula I has the structure:

where R³, R⁴, Y and n are as defined herein. In one embodiment, phenyloptionally substituted with one or more substituents independentlyselected from halogen, (1-4C)alkoxy, CF₃ and CHF₂. In one embodiment, Yis a 5-6 membered heteroaryl ring having a ring heteroatom selected fromN and S, wherein said heteroaryl ring is optionally substituted with oneor more halogen atoms. In one embodiment, R³ is hydrogen. In anotherembodiment, R³ is methyl. In one embodiment, n is 0, 1 or 2. In oneembodiment, n is 0. Particular examples of the ring at the 5-position ofFormula I when X is CH₂CH₂ include the structures:

In one embodiment, X is —CH₂O—. In one embodiment, the heterocyclic ringat the 5-position of Formula I has the structure:

where R³, R⁴, Y and n are as defined herein. In one embodiment, Y isphenyl optionally substituted with one or more substituentsindependently selected from halogen, (1-4C)alkoxy, CF₃ and CHF₂. In oneembodiment, Y is phenyl optionally substituted with one or moresubstituents independently selected from F and (1-4C)alkoxy. In oneembodiment, Y is a 5-6 membered heteroaryl ring having a ring heteroatomselected from N and S, wherein said heteroaryl ring is optionallysubstituted with one or more halogen atoms. In one embodiment, R³ ishydrogen. In another embodiment, R³ is methyl. In one embodiment, n is0, 1 or 2. Particular examples of the ring at the 5-position of FormulaI when X is —CH₂O— include the structures:

In one embodiment, X is —CH₂NR^(d)—. In one embodiment, the heterocyclicring at the 5-position of Formula I has the structure:

where R³, R⁴, Y, Rd and n are as defined herein. In one embodiment,R^(d) is H. In one embodiment, R^(d) is (1-4C alkyl), for examplemethyl, ethyl, propyl, isopropyl, or butyl. A particular example ismethyl. In one embodiment, Y is phenyl optionally substituted with oneor more substituents independently selected from halogen, (1-4C)alkoxy,CF₃ and CHF₂. In one embodiment, Y is a 5-6 membered heteroaryl ringhaving a ring heteroatom selected from N and S, wherein said heteroarylring is optionally substituted with one or more halogen atoms. In oneembodiment, n is 0. Particular examples of the ring at the 5-position ofFormula I when X is —CH₂NR^(d)— include the structures:

Compounds of Formula I include compound of Formula Ib, wherein

R¹ is H or (1-6C alkyl);

R² is NR^(b)R^(c);

NR^(b)R^(c) forms a 4 membered heterocyclic ring having a ring nitrogenatom, wherein said heterocyclic ring is optionally substituted with oneor more substituents independently selected from halogen, OH, (1-4Calkyl), (1-4C)alkoxy, —OC(═O)(1-4C alkyl), NH₂, —NHC(═O)O(1-4C alkyl)and (1-4C)hydroxyalkyl,

or NR^(b)R^(c) forms a 5-6 membered heterocyclic ring having a ringheteroatom which is nitrogen and optionally having a second ringheteroatom or group selected from N, O and SO₂, wherein the heterocyclicring is optionally substituted with one or more substituentsindependently selected from OH, halogen, CF₃, (1-4C)alkyl, CO₂(1-4Calkyl), CO₂H, NH₂, NHC(═O)O(1-4C alkyl) and oxo;

Y is phenyl optionally substituted with one or more substituentsindependently selected from halogen, (1-4C)alkoxy, CF₃ and CHF₂;

X is null, —CH₂—, or —CH₂CH₂—;

R³ is H or (1-4C alkyl);

each R⁴ is independently selected from halogen, (1-4C)alkyl, OH, (1-4C)alkoxy, NH₂, NH(1-4C alkyl) and CH₂OH; and

n is 0, 1, or 2.

In one embodiment of Formula Ib, Y is phenyl optionally substituted withone or more halogen atoms. In one embodiment of Formula Ib, Y is phenyloptionally substituted with one or two fluorine atoms.

In one embodiment of Formula Ib, NR^(b)R^(c) forms a 4 memberedheterocyclic ring having a ring nitrogen atom, wherein said ring isoptionally substituted with one or more substituents independentlyselected from halogen, OH, (1-4C alkyl), (1-4C)alkoxy, —OC(═O)(1-4Calkyl), NH₂, —NHC(═O)O(1-4C alkyl) and (1-4C)hydroxyalkyl, or (ii)NR^(b)R^(c) forms a 5-6 membered heterocyclic ring having a ringheteroatom which is nitrogen and optionally having a second ringheteroatom or group selected from N, O and SO₂, wherein the heterocyclicring is optionally substituted with one or more substituentsindependently selected from OH, halogen, CF₃, (1-4C)alkyl, CO₂(1-4Calkyl), CO₂H, NH₂, NHC(═O)O(1-4C alkyl) and oxo.

In one embodiment of Formula Ib, NR^(b)R^(c) forms a 5-6 memberedheterocyclic ring having a ring heteroatom which is nitrogen andoptionally having a second ring heteroatom or group selected from N, Oand SO₂, wherein the heterocyclic ring is optionally substituted withone or more substituents independently selected from OH, halogen, CF₃,(1-4C)alkyl, CO₂(1-4C alkyl), CO₂H, NH₂, NHC(═O)O(1-4C alkyl) and oxo.

In one embodiment of Formula Ib, n is zero or one.

In one embodiment of Formula Ib, R³ is hydrogen.

Compounds of Formula Ib include compounds of Formula Ic wherein:

R¹ is H or (1-6C alkyl);

R² is NR^(b)R^(c);

NR^(b)R^(c) forms a 4 membered heterocyclic ring having a ring nitrogenatom, wherein said heterocyclic ring is optionally substituted with oneor more substituents independently selected from halogen, OH, (1-4Calkyl), (1-4C)alkoxy, —OC(═O)(1-4C alkyl), NH₂, —NHC(═O)O(1-4C alkyl)and (1-4C)hydroxyalkyl;

Y is phenyl optionally substituted with one or more substituentsindependently selected from halogen, (1-4C)alkoxy, CF₃ and CHF₂;

X is —CH₂—;

R³ is H or (1-4C alkyl);

each R⁴ is independently selected from halogen, (1-4C)alkyl, OH, (1-4C)alkoxy, NH₂, NH(1-4C alkyl) and CH₂OH; and

n is 0, 1, or 2.

In one embodiment of Formula Ic, the heterocyclic ring formed byNR^(b)R^(c) is optionally substituted with one or two substituentsindependently selected from F, OH, methyl, OMe, OC(═O)C(CH₃)₂, NH₂,—NHC(═O)OC(CH₃)₃ and CH₂OH.

In one embodiment of Formula Ic, the heterocyclic ring formed byNR^(b)R^(c) is 4 membered azcyclic ring optionally substituted with oneor two substituents independently selected from OH, (1-4C alkyl), and—O(1-4C alkyl), for example OH, Me and OMe.

In one embodiment of Formula Ic, Y is phenyl optionally substituted withone or more halogen atoms. In one embodiment of Formula Ic, Y is phenyloptionally substituted with one or two fluorine atoms.

Compounds of Formula Ib also include compounds of Formula Id wherein:

R¹ is H or (1-6C alkyl);

R² is NR^(b)R^(c);

NR^(b)R^(c) forms a 5-6 membered heterocyclic ring having a ringheteroatom which is nitrogen and optionally having a second ringheteroatom or group selected from N, O and SO₂, wherein the heterocyclicring is optionally substituted with one or more substituentsindependently selected from OH, halogen, CF₃, (1-4C)alkyl, CO₂(1-4Calkyl), CO₂H, NH₂, NHC(═O)O(1-4C alkyl) and oxo;

Y is phenyl optionally substituted with one or more substituentsindependently selected from halogen, (1-4C)alkoxy, CF₃ and CHF₂;

X is —CH₂—;

R³ is H or (1-4C alkyl);

each R⁴ is independently selected from halogen, (1-4C)alkyl, OH, (1-4C)alkoxy, NH₂, NH(1-4C alkyl) and CH₂OH; and

n is 0, 1, or 2.

In one embodiment of Formula Id, the heterocyclic ring formed byNR^(b)R^(c) is optionally substituted with one or two substituentsindependently selected from OH, F, NH₂, CO₂H, CO₂Et, NHCO₂C(CH₃)₃, CF₃,methyl, ethyl, isopropyl, CO₂C(CH₂)₃ and oxo.

In one embodiment of Formula Id, the heterocyclic ring formed byNR^(b)R^(c) is a 5-6 membered azacyclic ring optionally substituted withone or more substituents independently selected from OH, F, NH₂, CO₂H,CO₂Et, NHCO₂C(CH₃)₃, CF₃, methyl, ethyl, isopropyl, CO₂C(CH₂)₃ and oxo.

In one embodiment of Formula Id, the heterocyclic ring formed byNR^(b)R^(c) is a 5 membered azacyclic ring optionally substituted withone or more substituents independently selected from OH, F, NH₂, CO₂H,CO₂Et, NHCO₂C(CH₃)₃, CF₃, methyl, ethyl, isopropyl, CO₂C(CH₂)₃ and oxo.

In certain embodiments of Formula Id, —NR^(b)R^(c) forms a 5-memberedazacyclic ring optionally substituted with one to two substitutedindependently selected from OH and Me.

In one embodiment of Formula Id, the heterocyclic ring formed byNR^(b)R^(c) is a 6 membered azacyclic ring optionally substituted withone or more substituents independently selected from OH, F, NH₂, CO₂H,CO₂Et, NHCO₂C(CH₃)₃, CF₃, methyl, ethyl, isopropyl, CO₂C(CH₂)₃ and oxo.

In one embodiment of Formula Id, the heterocyclic ring formed byNR^(b)R^(c) is a 6 membered azacyclic ring optionally substituted withone or two substituents independently selected from OH and (1-4C) alkyl,for example OH and Me.

In one embodiment of Formula Id, Y is phenyl optionally substituted withone or more halogen atoms. In one embodiment of Formula Id, Y is phenyloptionally substituted with one or two fluorine atoms.

In one embodiment of Formula Ic or Id, n is zero or one.

In one embodiment of Formula Ic or Id, R³ is hydrogen.

In one embodiment of Formula Ic or Id, R¹ is hydrogen.

Compounds of Formula I include compound of Formula Ie, wherein:

R¹ is H or (1-6C alkyl);

R² is NR^(b)R^(c);

NR^(b)R^(c) forms a 4 membered heterocyclic ring having a ring nitrogenatom, wherein said heterocyclic ring is optionally substituted with oneor more substituents independently selected from halogen, OH, (1-4Calkyl), (1-4C)alkoxy, —OC(═O)(1-4C alkyl), NH₂, —NHC(═O)O(1-4C alkyl)and (1-4C)hydroxyalkyl,

or NR^(b)R^(c) forms a 5-6 membered heterocyclic ring having a ringheteroatom which is nitrogen and optionally having a second ringheteroatom or group selected from N, O and SO₂, wherein the heterocyclicring is optionally substituted with one or more substituentsindependently selected from OH, halogen, CF₃, (1-4C)alkyl, CO₂(1-4Calkyl), CO₂H, NH₂, NHC(═O)O(1-4C alkyl) and oxo;

Y is a 5-6 membered heteroaryl ring having a ring heteroatom selectedfrom N and S, wherein said heteroaryl ring is optionally substitutedwith one or more halogen atoms;

X is null, —CH₂—, or —CH₂CH₂—;

R³ is H or (1-4C alkyl);

each R⁴ is independently selected from halogen, (1-4C)alkyl, OH, (1-4C)alkoxy, NH₂, NH(1-4C alkyl) and CH₂OH; and

n is 0, 1, or 2.

Compounds of Formula I include compounds of Formula If, wherein:

R¹ is H or (1-6C alkyl);

R² is (1-4C)alkyl, (1-4C)fluoroalkyl, CF₃, (1-4C)hydroxyalkyl, -(1-4Calkyl)hetAr¹, -(1-4C alkyl)NH₂, -(1-4C alkyl)NH(1-4C alkyl), -(1-4Calkyl)N(1-4C alkyl)₂, hetAr², hetCyc¹, hetCyc², phenyl which isoptionally substituted with NHSO₂(1-4C alkyl), or (3-6C)cycloalkyl whichis optionally substituted with (1-4C alkyl), CN, OH, OMe, NH₂, NHMe,N(CH₃)₂, F, CF₃, CO₂(1-4C alkyl), CO₂H, C(═O)NR^(e)R^(f) or C(═O)OR^(g);

hetAr¹ is a 5-membered heteroaryl ring having 1-3 ring nitrogen atoms;

hetAr² is 5-6 membered heteroaryl ring having at least one nitrogen ringatom and optionally having a second ring heteroatom independentlyselected from N and S, wherein said heteroaryl ring is optionallysubstituted with one or more substituents independently selected from(1-4C alkyl), halogen, -(1-4C)alkoxy, and NH(1-4C alkyl);

hetCyc¹ is a carbon-linked 4-6 membered azacyclic ring optionallysubstituted with one or more substituents independently selected from(1-4C alkyl), and CO₂(1-4C alkyl);

hetCyc² is a pyridinone or pyridazinone ring which is optionallysubstituted with a substituent selected from (1-4C)alkyl;

R^(e) is H or (1-4C)alkyl;

R^(f) is H, (1-4C)alkyl, or (3-6C)cycloalkyl;

or NR^(e)R^(f) forms a 5-6-membered azacyclic ring optionally having anadditional ring heteroatom selected from N and O, wherein the azacyclicring is optionally substituted with OH;

R^(g) is H or (1-6C)alkyl;

Y is (i) phenyl optionally substituted with one or more substituentsindependently selected from halogen, (1-4C)alkoxy, CF₃ and CHF₂, or (ii)a 5-6 membered heteroaryl ring having a ring heteroatom selected from Nand S, wherein said heteroaryl ring is optionally substituted with oneor more halogen atoms;

X is null, —CH₂—, —CH₂CH₂—;

R^(d) is H or (1-4C alkyl);

R³ is H or (1-4C alkyl);

each R⁴ is independently selected from halogen, (1-4C)alkyl, OH,(1-4C)alkoxy, NH₂, NH(1-4C alkyl) and CH₂OH; and

n is 0, 1, 2, 3, 4, 5 or 6.

In one embodiment of Formula If, Y is phenyl optionally substituted withone or more substituents independently selected from halogen,(1-4C)alkoxy, CF₃ and CHF₂.

In one embodiment of Formula If, Y is a 5-6 membered heteroaryl ringhaving a ring heteroatom selected from N and S, wherein said heteroarylring is optionally substituted with one or more halogen atoms.

In one embodiment of Formula If, R² is selected from (1-4C)alkyl,(1-4C)fluoroalkyl, CF₃, -(1-4C)hydroxyalkyl, (1-4C alkyl)hetAr¹, and-(1-4C alkyl)NH(1-4C alkyl)

In one embodiment of Formula If, R² is selected from methyl, isopropyl,tert-butyl, CF(CH₃)₂, CF₃, C(CH₃)₂OH and C(CH₃)₂CH₂OH,2-(1,2,4-triazolyl)propan-2-yl, and —C(CH₃)₂NHCH₃.

In one embodiment of Formula If, R² is a cyclopropyl, cyclobutyl andcyclopentyl ring optionally substituted with (1-4C alkyl), CN, OH, CF₃,CO₂(1-4C alkyl) or CO₂H.

In one embodiment of Formula If, R² is selected from hetAr², hetCyc¹,and hetCyc².

In one embodiment of Formula If, R² is selected from (i) pyridyl,pyrimidyl, pyrazinyl, pyrazolyl, imidazolyl and thiazolyl ringsoptionally substituted with one or more substituents independentlyselected from (1-4C alkyl), halogen, (1-4C)alkoxy and NH(1-4C alkyl);(ii) carbon-linked azetidinyl, pyrrolidinyl and piperidinyl ringsoptionally substituted with one or more substituents independentlyselected from (1-4C alkyl), CO₂H and CO₂(1-4C alkyl); and (iii) apyridinone or pyridazinone ring which is optionally substituted with asubstituent selected from (1-4C)alkyl.

In one embodiment of Formula If, R² is C(═O)NR^(e)R^(f) or C(═O)OR^(g).

Compounds of Formula I include compound of Formula Ig, wherein

R¹ is H or (1-6C alkyl);

R² is NR^(b)R^(c);

R^(b) is H or (1-6C alkyl);

R^(c) is H, (1-4C)alkyl, (1-4C)hydroxyalkyl, hetAr³, or phenyl, whereinsaid phenyl is optionally substituted with one or more substituentsindependently selected from halogen, CN, CF₃ and —O(1-4C alkyl);

hetAr³ is a 5-6 membered heteroaryl ring having 1-2 ring heteroatomsindependently selected from N and O and optionally substituted with oneor more substituents independently selected from (1-4C)alkyl;

Y is (i) phenyl optionally substituted with one or more substituentsindependently selected from halogen, (1-4C)alkoxy, CF₃ and CHF₂, or (ii)a 5-6 membered heteroaryl ring having a ring heteroatom selected from Nand S, wherein said heteroaryl ring is optionally substituted with oneor more halogen atoms;

X is null, —CH₂—, or —CH₂CH₂—;

R^(d) is H or (1-4C alkyl);

R³ is H or (1-4C alkyl);

each R⁴ is independently selected from halogen, (1-4C)alkyl, OH,(1-4C)alkoxy, NH₂, NH(1-4C alkyl) and CH₂OH; and

n is 0, 1, 2, 3, 4, 5 or 6.

In one embodiment of Formula Ig, Y is phenyl optionally substituted withone or more substituents independently selected from halogen,(1-4C)alkoxy, CF₃ and CHF₂.

In one embodiment of Formula Ig, Y is a 5-6 membered heteroaryl ringhaving a ring heteroatom selected from N and S, wherein said heteroarylring is optionally substituted with one or more halogen atoms.

In one embodiment of Formula Ig, R^(c) is selected from H, Me, t-butyl,CH₂CH₂OH and CH₂CH₂CH₂OH, dimethylisoxazolyl, phenyl, fluorophenyl,chlorophenyl, cyanophenyl, methoxyphenyl, trifluoromethylphenyl,dichlorophenyl, and trimethoxyphenyl. More particular examples include4-fluorophenyl, 3-chlorophenyl, 4-chlorophenyl, 3-cyanophenyl,4-cyanophenyl, 4-methoxyphenyl, 2-4-dichlorophenyl,3-(trifluoromethyl)phenyl, 3,5-dichlorophenyl, and3,4,5-trimethoxyphenyl.

In one embodiment of Formula Ig, n is 0, 1 or 2.

It will be appreciated that certain compounds according to the inventionmay contain one or more centers of asymmetry and may therefore beprepared and isolated in a mixture of isomers such as a racemic ordiastereomeric mixture, or in an enantiomerically pure form. It isintended that all stereoisomeric forms of the compounds of theinvention, including but not limited to, diastereomers, enantiomers andatropisomers, as well as mixtures thereof such as racemic mixtures, formpart of the present invention.

In the structures shown herein, where the stereochemistry of anyparticular chiral atom is not specified, then all stereoisomers arecontemplated and included as the compounds of the invention. Wherestereochemistry is specified by a solid wedge or dashed linerepresenting a particular configuration, then that stereoisomer is sospecified and defined.

It will also be appreciated that certain compounds of Formula I may beused as intermediates for further compounds of Formula I.

The compounds of Formula I include pharmaceutically acceptable saltsthereof. In addition, the compounds of Formula I also include othersalts of such compounds which are not necessarily pharmaceuticallyacceptable salts, and which may be useful as intermediates for preparingand/or purifying compounds of Formula I and/or for separatingenantiomers of compounds of Formula I. Examples of particular saltsinclude hydrogen sulfate salts, hydrochloride salts and trifluoroacetatesalts.

It will further be appreciated that the compounds of Formula I and theirsalts may be isolated in the form of solvates, and accordingly that anysuch solvate is included within the scope of the present invention.

The compounds of Formula I also include compounds that differ only inthe presence of one or more isotopically enriched atoms. For example,compounds of the invention include compounds wherein one or morehydrogen atoms are replaced deuterium or tritium, or one or more carbonatoms are replaced by a ¹³C- or ¹⁴C-enriched carbon are within the scopeof this invention.

The term “(1-4C) alkyl” as used herein refers to saturated linear orbranched-chain monovalent hydrocarbon radicals of one to four carbonatoms, respectively. Examples include, but are not limited to, methyl,ethyl, 1-propyl, 2-propyl, 1-butyl, 2-methyl-1-propyl, 2-butyl, and2-methyl-2-propyl.

The term “(1-4C) alkoxy” as used herein refers to saturated linear orbranched-chain monovalent radicals of one to four carbon atoms,respectively, wherein the radical is on the oxygen atom.

The term “(1-4C)hydroxyalkyl” as used herein refers to saturated linearor branched-chain monovalent hydrocarbon radicals of one to four carbonatoms, respectively, wherein one of the hydrogen atoms is replaced withan OH group.

The term “halogen” includes fluoro, chloro, bromo and iodo.

According to another aspect, the present invention provides a processfor the preparation of a compound of Formula I or a pharmaceuticallyacceptable salt thereof as defined herein which comprises:

(a) for a compound of Formula I wherein R² is NR^(b)R^(c), reacting acorresponding compound of formula II

with a compound having the formula HNR^(b)R^(c) in the presence of acoupling reagent; or

(b) for a compound of Formula I wherein R² is NR^(b)R^(c) and R^(b) isH, reacting a corresponding compound of formula II with a compoundhaving the formula O═C═N—R^(c); or

(c) for a compound of Formula I wherein R² is hetAr² or a phenyl ringwhich is optionally substituted with NHSO₂(1-4C alkyl), reacting acorresponding compound of Formula II with a corresponding compoundhaving the formula HOC(═O)R² in the presence of a coupling reagent and abase; or

(d) for a compound of Formula I wherein R² is (1-4C)alkyl,(1-4C)fluoroalkyl, CF₃, (1-4C)hydroxyalkyl, or (3-6C)cycloalkyl which isoptionally substituted with (1-4C alkyl), CN, OH, CF₃, CO₂(1-4C alkyl)or CO₂H, reacting a corresponding compound of Formula II with acorresponding compound having the formula (R²CO)₂O in the presence of abase; or

(e) for a compound of Formula I wherein R² is (1-4C)alkyl,(1-4C)fluoroalkyl, CF₃, (1-4C)hydroxyalkyl, or (3-6C)cycloalkyl which isoptionally substituted with (1-4C alkyl), CN, OH, CF₃, CO₂(1-4C alkyl)or CO₂H, reacting a corresponding compound of Formula II with acorresponding compound having the formula HOC(═O)R² in the presence of acoupling reagent and a base; or

(f) for a compound of Formula I wherein R² is C(═O)NR^(e)R^(f), reactinga compound of formula VII

with a compound having the formula HNR^(e)R^(f) in the presence of abase; or

(g) for a compound of Formula I wherein R² is C(═O)OR^(g), reacting acompound of Formula II with methyl 2-chloro-2-oxoacetate, and treatingwith an alkali hydroxide to prepare a compound of formula I where R^(g)is H; and

removing or adding any protecting groups if desired, and forming a saltif desired.

Referring to methods (a) and (e), examples of suitable coupling reagentsinclude CDI (carbonyl diimidazole), phosgene, and bis(trichloromethyl)carbonate. The reaction is optionally performed in the presence of atertiary amine base, such as DIEA (diisopropylethylamine). Suitablesolvents include dichloromethane, dichloroethane, THF, and DMF. Thereaction is conveniently performed at ambient temperature.

Compounds of formula II

can be prepared by reducing a corresponding compound of formula III

under standard reducing conditions, for example reacting a compound offormula II with zinc dust under acidic conditions, such as in thepresence of NH₄Cl (saturated aqueous), HCl, or acetic acid. Anotherexample of such standard reducing conditions includes reacting compoundsof formula III under a hydrogen atmosphere in the presence of a preciousmetal catalyst to corresponding compounds of formula II.

Compounds of Formula III can be prepared by nitrating a correspondingcompound having the formula IV

using standard nitrating conditions known in the art, for example byreacting a corresponding compound of Formula IV with nitric acid in thepresence of an activating agent such as TFA or concentrated sulfuricacid.

Compounds of the formula IV can be prepared by coupling a correspondingcompound of Formula V

where Z is a leaving group or atom, such as a halogen (for example Cl),with a corresponding compound having the formula VI

where R³, R⁴, n, X and Y are as defined herein, in a suitable solventsuch as an alcohol (for example n-butanol or isopropanol), at elevatedtemperatures, for example at temperatures between 100 and 180° C., forexample at a temperature of about 140° C. Compounds of Formula V arecommercially available or can be prepared by standard methods known inthe art.

Compounds of Formula II and III are also believed to be novel andprovide a further embodiment of this invention.

Referring to method (b), suitable solvents include dichloromethane,dichloroethane, THF, and DMF. The reaction is conveniently performed atambient temperature.

Referring to method (c), suitable coupling reagents include HATU, HBTU,TBTU, DCC (N,N′-dicyclohexylcarbodiimide), DIEC(1-(3-dimethylaminopropyl)-3-ethylcarboiimide) and any other amidecoupling reagents well known to persons skilled in the art. Suitablebases include tertiary amine bases such as diisopropylethylamine (DIEA)and triethylamine. Suitable solvents include DMF and CH₃CN. The reactionis conveniently performed at temperatures between 0° C. and ambienttemperature.

Referring to method (d), suitable bases include amine bases such aspyridine or triethylamine, and suitable coupling reagents include HATU,HBTU, TBTU, DCC (N,N′-dicyclohexylcarbodiimide), DIEC(1-(3-dimethylaminopropyl)-3-ethylcarboiimide) and any other amidecoupling reagents well known to persons skilled in the art. Suitablesolvents include dichloromethane and dichloroethane. The reaction isconveniently performed at temperatures between 0° C. and ambienttemperature.

The ability of compounds to act as TrkA inhibitors may be demonstratedby the assays described in Examples A and B. The ability of compounds toact as TrkB inhibitors may be demonstrated by the assay described inExample B.

Compounds of Formula I are useful for treating chronic and acute pain,including pain associated with cancer, surgery, and bone fracture.Certain compounds which are inhibitors of TrkA and/or TrkB may be usefulin the treatment of multiple types of pain including inflammatory pain,neuropathic pain, and pain associated with cancer, surgery, and bonefracture.

Compounds of Formula I are also useful for treating cancers includingneuroblastoma, ovarian, pancreatic and colorectal cancer.

Compounds of Formula I are also useful for treating inflammation andcertain infectious diseases.

In addition, compounds of Formula I may also be used to treatinterstitial cystitis (IC), painful bladder syndrome (PBS), urinaryincontinence, asthma, anorexia, atopic dermatitis, and psoriasis.

Compounds of Formula I may also be used to treat demyelination anddysmyelination by promoting myelination, neuronal survival, andoligodendrocyte differentiation via blocking Sp35-TrkA interaction.

Compounds of Formula I which are dual inhibitors of TrkA and TrkB may beuseful in the treatment of multiple types of pain including inflammatorypain, neuropathic pain, surgical pain and pain associated with cancer.

Compounds of Formula I may be of therapeutic value for the useful in thetreatment of bone-related diseases (such as those involving boneresorption). Examples of bone-related diseases include metastatic bonedisease, treatment-induced bone loss, osteoporosis, rheumatoidarthritis, ankylosing spondylitis, Paget's disease, and periodontaldisease. The osteoporosis may be attributed to (1) menopause in women,(2) aging in men or women, (3) suboptimal bone growth during childhoodand adolescence that resulted in failure to reach peak bone mass, and/or(4) bone loss secondary to other disease conditions, eating disorders,medications and/or medical treatments.

Other osteolytic diseases that can be treated according to the presentinvention are more localized. A particular example is metastatictumor-induced osteolysis. In this condition, bone cancers or bonemetastases induce localized osteolysis that causes pain, bone weaknessand fractures. Such localized osteolysis also permits tumors to growlarger by creating more space for them in the bone and releasing growthfactors from the bone matrix. Cancers presently known to causetumor-induced osteolysis include hematological malignancies (e.g.,myeloma and lymphoma) and solid tumors (e.g., breast, prostate, lung,renal and thyroid), all of which the present invention contemplatestreating.

As used herein, the term treatment includes prophylaxis as well astreatment of an existing condition.

Accordingly, another aspect of this invention provides a method oftreating diseases or medical conditions in a mammal, wherein saiddisease or condition is treatable with an inhibitor of TrkA and/or TrkB,comprising administering to said mammal one or more compounds of FormulaI or a pharmaceutically acceptable salt thereof in an amount effectiveto treat or prevent said disorder. In a particular embodiment, theinvention provides a method of treating pain, cancer, inflammation,neurodegenerative disease or Typanosoma cruzi infection in a mammal,which comprises administering to said mammal a therapeutically effectiveamount of a compound of Formula I, or a pharmaceutically acceptable saltthereof.

In another embodiment, the invention provides a method of treatingosteolytic disease in a mammal, which comprises administering to saidmammal a therapeutically effective amount of a compound of Formula I ora pharmaceutically acceptable salt thereof.

The compounds of the present invention can be used in combination withone or more additional drugs that work by the same or a differentmechanism of action. Such conjoint treatment may be achieved by way ofthe simultaneous, sequential or separate administration of theindividual components of the treatment. Examples includeanti-inflammatory compounds, steroids (e.g., dexamethasone, cortisoneand fluticasone), analgesics such as NSAIDs (e.g., aspirin, ibuprofen,indomethacin, and ketoprofen), and opioids (such as morphine), andchemotherapeutic agents.

In the field of medical oncology it is normal practice to use acombination of different forms of treatment to treat each patient withcancer. In medical oncology the other component(s) of such conjointtreatment in addition to compositions of the present invention may be,for example, surgery, radiotherapy, chemotherapy, signal transductioninhibitors and/or monoclonal antibodies.

Accordingly, the compounds of Formula I may be administered incombination with one or more agents selected from mitotic inhibitors,alkylating agents, anti-metabolites, antisense DNA or RNA, intercalatingantibiotics, growth factor inhibitors, signal transduction inhibitors,cell cycle inhibitors, enzyme inhibitors, retinoid receptor modulators,proteasome inhibitors, topoisomerase inhibitors, biological responsemodifiers, anti-hormones, angiogenesis inhibitors, cytostatic agentsanti-androgens, targeted antibodies, HMG-CoA reductase inhibitors, andprenyl-protein transferase inhibitors.

The phrase “effective amount” means an amount of compound that, whenadministered to a mammal in need of such treatment, is sufficient to (i)treat or prevent a particular disease, condition, or disorder which canbe treated with an inhibitor of TrkA and/or TrkB, (ii) attenuate,ameliorate, or eliminate one or more symptoms of the particular disease,condition, or disorder, or (iii) prevent or delay the onset of one ormore symptoms of the particular disease, condition, or disorderdescribed herein.

The amount of a compound of Formula I that will correspond to such anamount will vary depending upon factors such as the particular compound,disease condition and its severity, the identity (e.g., weight) of themammal in need of treatment, but can nevertheless be routinelydetermined by one skilled in the art.

As used herein, the term “mammal” refers to a warm-blooded animal thathas or is at risk of developing a disease described herein and includes,but is not limited to, guinea pigs, dogs, cats, rats, mice, hamsters,and primates, including humans.

Compounds of the invention may be administered by any convenient route,e.g. into the gastrointestinal tract (e.g. rectally or orally), thenose, lungs, musculature or vasculature, or transdermally or dermally.Compounds may be administered in any convenient administrative form,e.g. tablets, powders, capsules, solutions, dispersions, suspensions,syrups, sprays, suppositories, gels, emulsions, patches etc. Suchcompositions may contain components conventional in pharmaceuticalpreparations, e.g. diluents, carriers, pH modifiers, sweeteners, bulkingagents, and further active agents. If parenteral administration isdesired, the compositions will be sterile and in a solution orsuspension form suitable for injection or infusion. Such compositionsform a further aspect of the invention.

According to another aspect, the present invention provides apharmaceutical composition, which comprises a compound of Formula I or apharmaceutically acceptable salt thereof, as defined hereinabove. In oneembodiment, the pharmaceutical composition includes the compound ofFormula I together with a pharmaceutically acceptable diluent orcarrier.

According to another aspect, the present invention provides a compoundof Formula I or a pharmaceutically acceptable salt thereof, for use intherapy, such as the treatment of a condition treatable with aninhibitor or TrkA and/or TrkB, such as a TrkA and/or TrkB mediatedcondition, such as one or more conditions described herein.

According to a further aspect, the present invention provides the use ofa compound of Formula I or a pharmaceutically acceptable salt thereof,in the treatment of a condition that can be treated with an inhibitor ofTrkA and/or TrkB, such as a TrkA and/or TrkB mediated condition, such asa condition as defined hereinabove. In one embodiment, the inventionprovides a compound of Formula I, or a pharmaceutically acceptable saltthereof, for use in the treatment of pain, cancer, inflammation,neurodegenerative disease or Typanosoma cruzi infection.

In one embodiment, a compound of the invention is selected from any oneof:

-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide;-   (R)-3-(5-(2-(2,5-di    fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1,1-dimethylurea;-   (R)-1-tert-butyl-3-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)urea;-   (R)-1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-phenylurea;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)isobutyramide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-methyl-6-oxo-1,6-dihydropyridazine-3-carboxamide;-   (R)—N-(5-(4,4-difluoro-2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide;-   (R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide;-   N-(5-(2-(3-fluorophenyl)-2-methylpyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide;-   (R)—N-(5-(2-(3-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide;-   (R)—N-(5-(2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide;-   (S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (3R,4R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3,4-dihydroxypyrrolidine-1-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methoxyazetidine-1-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-3-methylazetidine-1-carboxamide;-   (R)-1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-(4-fluorophenyl)urea;-   (R)-1-(4-chlorophenyl)-3-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)urea;-   (R)-1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-(4-methoxyphenyl)urea;-   (R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methoxyazetidine-1-carboxamide;-   (R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-3-methylazetidine-1-carboxamide;-   (R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide;-   (S)-tert-butyl    4-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-2-methylpiperazine-1-carboxylate;-   (S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpiperazine-1-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-isopropylpiperazine-1-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-ethylpiperazine-1-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-methylpiperazine-1-carboxamide;-   N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3,5-dimethylpiperazine-1-carboxamide;-   (S)-tert-butyl    4-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-2-methylpiperazine-1-carboxylate;-   (S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpiperazine-1-carboxamide    hydrochloride;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide;-   (R)-methyl    1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)cyclopropanecarboxylate;-   (R)-1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl    carbamoyl)cyclopropanecarboxylic acid;-   (S)—N-(5-((R)-2-(3-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (R)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (S)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (R)—N-(5-(2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-hydroxypiperidine-1-carboxamide;-   (R)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide;-   (S)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide;-   (R)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-hydroxypiperidine-1-carboxamide;-   (R)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide;-   (S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)pivalamide;-   (R)-tert-butyl    3-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)azetidine-1-carboxylate;-   (R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)azetidine-3-carboxamide;-   (R)-tert-butyl    4-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-4-methylpiperidine-1-carboxylate;-   (R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-methylpiperidine-4-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-hydroxy-2-methylpropanamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-(trifluoromethyl)cyclopropanecarboxamide;-   (R)-1-cyano-N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)cyclopropanecarboxamide;-   (R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-methylpyrrolidine-2-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-fluoro-2-methylpropanamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-(isopropylamino)thiazole-4-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-methyl-2-(1H-1,2,4-triazol-1-yl)propanamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)pyrazine-2-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-5-methylpyrazine-2-carboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)picolinamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-6-methylpicolinamide;-   (R)-5-chloro-N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)picolinamide;-   (R)-4-chloro-N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)picolinamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpicolinamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-2,2-dimethylpropanamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-hydroxycyclopropanecarboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-methyl-2-(methylamino)propanamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)pyrimidine-2-carboxamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)picolinamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpicolinamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-methyl-2-oxo-1,2-dihydropyridine-4-carboxamide;-   (R)-6-chloro-N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)picolinamide;-   (R)-4-(ethylsulfonamido)-N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)benzamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-methyl-1H-pyrazole-3-carboxamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1H-pyrazole-3-carboxamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-6-methoxypicolinamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)nicotinamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)isonicotinamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-6-methylnicotinamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-methoxynicotinamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylisonicotinamide;-   (S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-5-methylpyrazine-2-carboxamide;-   (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-methyl-1H-imidazole-2-carboxamide;-   (S)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (R)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (R)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide;-   (S)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide;-   (S)—N-(5-((R)-2-(5-fluoropyridin-3-yl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (R)—N-(5-((R)-2-(5-fluoropyridin-3-yl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (S)—N-(5-((R)-2-(5-fluoro-2-methoxyphenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (S)—N-(5-((R)-2-(5-fluoro-2-methoxyphenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide;-   (1S,4S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-oxa-5-azabicyclo[2.2.1]heptane-5-carboxamide;-   (R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide;-   (1S,3R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxycyclopentanecarboxamide;-   (1S,3S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxycyclopentanecarboxamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxycyclobutanecarboxamide;-   (R)—N¹-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-N²,N²-dimethyloxalamide;-   (R)—N¹-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-N²-methyloxalamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)oxalamide;-   (R)—N-cyclopropyl-N¹-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)oxalamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-(3-hydroxyazetidine-1-yl)-2-oxoacetamide;-   N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-((S)-3-hydroxypyrrolidin-1-yl)-2-oxoacetamide;-   (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-morpholino-2-oxoacetamide;-   (R)-methyl    2-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylamino)-2-oxoacetate;-   (R)-2-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylamino)-2-oxoacetic    acid;

and salts thereof.

Particular examples of salts of the above compounds include hydrogensulfate salts, hydrochloride salts and trifluoroacetate salts.

EXAMPLES

The following examples illustrate the invention. In the examplesdescribed below, unless otherwise indicated all temperatures are setforth in degrees Celsius. Reagents were purchased from commercialsuppliers such as Aldrich Chemical Company, Lancaster, TCI or Maybridge,and were used without further purification unless otherwise indicated.Tetrahydrofuran (THF), dichloromethane (DCM, methylene chloride),toluene, and dioxane were purchased from Aldrich in Sure/Seal™ bottlesand used as received.

The reactions set forth below were done generally under a positivepressure of nitrogen or argon or with a drying tube (unless otherwisestated) in anhydrous solvents, and the reaction flasks were typicallyfitted with rubber septa for the introduction of substrates and reagentsvia syringe. Glassware was oven dried and/or heat dried.

Column chromatography was done on a Biotage system (Manufacturer: DyaxCorporation) having a silica gel or C-18 reverse phase column, or on asilica SepPak cartridge (Waters).

Acronyms found in the examples have the following meanings:

CDI carbonyldiimidazole DIEA diisopropylethylamine DCM dichloromethaneDME dimethoxyethane DMF dimethylformamide DMSO dimethylsulfoxide HATUO-(7-azabenzotriazol-1-yl)-1,1,3,3- tetramethyluroniumhexafluorophosphate PS-DMAP polystyrene-bound dimethylaminopyridine TFAtrifluoroacetic acid

Example A TrkA ELISA Assay

An enzyme-linked immunosorbant assay (ELISA) was used to assess TrkAkinase activity in the presence of inhibitors. Immulon 4HBX 384-wellmicrotiter plates (Thermo part #8755) were coated with a 0.025 mg/mLsolution of poly (Glu, Ala, Tyr; 6:3:1; Sigma P3899). Variousconcentrations of test compound, 2.5 nM TrkA (Invitrogen Corp.,histidine-tagged recombinant human TrkA, cytoplasmic domain), and 500 μMATP were incubated for 25 minutes at ambient temperature in the coatedplates while shaking. The assay buffer consisted of 25 mM MOPS pH 7.5,0.005% (v/v) Triton X-100 and 5 mM MgCl₂. The reaction mixture wasremoved from the plate by washing with PBS containing 0.1% (v/v) Tween20. The phosphorylated reaction product was detected using 0.2 μg/mL ofa phosphotyrosine specific monoclonal antibody (clone PY20) conjugatedto horseradish peroxidase in conjunction with the TMB PeroxidaseSubstrate System (KPL). After the addition of 1M phosphoric acid, thechromogenic substrate color intensity was quantitated via absorbance at450 nm. IC₅₀ values were calculated using either a 4 or 5-parameterlogistic curve fit.

In this assay, compounds of the invention had an average IC₅₀ below 1000nM. Certain compounds had an average IC₅₀ below 100 nM. Table 1 providesspecific IC₅₀ values for compounds of this invention when tested in thisassay.

TABLE 1 TrkA Elisa Enzyme Example No. IC₅₀ (nM) 1 20.7 2 15.8 3 22.2 4 55 12.1 6 19.2 7 77.5 8 13.7 9 820.8 10 187.9 11 171 12 26.5 13 32.2 149.7 15 13.3 16 27.5 17 19.7 18 4.6 19 10.1 20 4.8 21 27.9 22 11.5 2341.7 24 55 25 82.3 26 45 27 106.7 28 57.4 29 98 30 153.7 31 88.3 32115.6 33 4.7 34 98.2 35 20.2 36 18 37 8.7 38 85.5 39 25.7 40 30.8 41 4.142 28.3 43 11.7 44 13.4 45 6.3 46 37.3 47 190.3 48 15.3 49 29.2 50 12.451 5.2 52 4.2 53 31 54 14.2 55 3.1 56 14.4 57 2.2 58 3.1 59 1.7 60 4.261 4 62 4 63 1.7 64 7.5 65 16.5 66 52.5 67 3 68 4 69 6.2 70 55.6 71 3.572 45.5 73 8.5 74 15.3 75 7.4 76 53.3 77 71.8 78 47 79 5.7 80 320.2 81 882 6.6 83 35.4 84 3.2 85 5.7 86 14 87 14.6 88 156.1 89 896.1 90 11.3 9110.2 92 107.4 93 28.5 94 20.3 95 42.5 96 27.4 97 47.45 98 7.65 99 4.65100 15.85 101 10.1 102 12.75 103 82.4 104 7.65 105 4.7

Example B TrkA and TrkB Omnia Assay

Trk enzymatic selectivity was assessed using Omnia™ Kinase Assayreagents from Invitrogen Corp. Enzyme (either TrkA or TrkB fromInvitrogen Corp.) and test compound (various concentrations) wereincubated for 10 minutes at ambient temperature in a 384-well whitepolypropylene plate (Nunc catalog#267462). Omnia Tyr Peptide #4 (forTrkA) or #5 (for TrkB), as well as ATP, were then added to the plate.Final concentrations were as follows: 20 nM enzyme, 500 μM of ATP forTrkA assay or 1 mM ATP for TrkB assay, 10 μM peptide substrate. Theassay buffer consisted of 25 mM MOPS pH 7.5, 0.005% (v/v) Triton X-100and 5 mM MgCl₂. The production of phosphorylated peptide was monitoredcontinuously for 70 minutes using a Molecular Devices FlexStation II³⁸⁴microplate reader (excitation=360 nm; emission=485 nm). Initial rateswere calculated from the progress curves. IC₅₀ values were thencalculated from these rates using either a 4 or 5-parameter logisticcurve fit.

In this assay, compounds of the invention had an average IC₅₀ below 1000nM. Certain compounds had an average IC₅₀ below 100 nM.

Preparation A

Preparation of (R)-2-(2,5-difluorophenyl)pyrrolidine Step A: Preparationof (R)-tert-butyl 2-(2,5-difluorophenyl)pyrrolidine-1-carboxylate

A solution of tert-butylpyrrolidine-1-carboxylate (20 g, 116.8 mmol) and(−)sparteine (32.9, 140 mmol) in MTBE (360 mL) was cooled to −78° C.,and sec-BuLi (100 mL, 140 mmol, 1.4 M in cyclohexane) was introduceddropwise via cannula, keeping the internal temperature under −70° C. Theresulting solution was stirred for 3 hours at −78° C., followed byaddition of a solution of ZnCl₂ (93.4 mL, 93.4 mmol, 1M in Et₂O)drop-wise with rapid stirring, keeping the internal temperature below−65° C. The resulting light suspension was stirred at −78° C. for 30minutes and then warmed to ambient temperature. The resulting mixturewas charged with 2-bromo-1,4-difluorobenzene (14.5 mL, 128 mmol),followed by Pd(OAc)₂ (1.31 g, 5.8 mmol) and t-Bu₃P—HBF₄ (2.03 g, 7.0mmol) in one portion. After stirring overnight at ambient temperature,10.5 mL of NH₄OH solution was added and the reaction was stirred foranother hour. The resulting slurry was filtered through CELITE andwashed with Et₂O (1 L). The filtrate was washed with HCl (0.5 L, 1M aq.)and brine. The organic layer was filtered and concentrated, and thecrude product was purified by silica column chromatography, eluting with5-10% EtOAc/hexanes to give product (R)-tert-butyl2-(2,5-difluorophenyl)pyrrolidine-1-carboxylate as yellow oil (23.9 g,72% yield).

Step B: Preparation of (R)-2-(2,5-difluorophenyl)pyrrolidine

To (R)-tert-butyl 2-(2,5-difluorophenyl)pyrrolidine-1-carboxylate (23.9g, 84.4 mmol) was added 56.2 mL 4N HCl (dioxane). After stirring atambient temperature for 2 hours, 200 mL of ether was added and themixture was stirred for 10 minutes. The resulting slurry was filtered,yielding the hydrochloride salt of the product as a white solid (17.2g). To obtain the free base, the HCl salt product was dispersed in amixture of EtOAc (200 mL) and NaOH solution (100 mL, 2 N aq.) The layerswere separated and the aqueous layer was extracted with EtOAc. Thecombined organic extracts were filtered and concentrated to give thedesired product as a liquid (13.2 g, 85% yield).

Step C: Determination of Enantiomeric Excess (ee %) of(R)-2-(2,5-difluorophenyl)pyrrolidine

To an ethanol solution of (R)-2-(2,5-difluorophenyl)pyrrolidine wasadded excess N-(2,4-dinitro-5-fluorophenyl)-L-alanine amide (FDAA,Marfey's reagent). The mixture was heated to reflux for approximatelytwo minutes. After cooling to ambient temperature, the reaction mixturewas diluted with acetonitrile and injected onto HPLC (YMC ODS-AQ 4.6×50mm 3 μm 120 Å column; mobile phase: 5-95% solvent B in A; solvent A:H₂O/1% IPA/10 mM ammonium acetate, and solvent B: ACN/1% IPA/10 mMammonium acetate; flow rate: 2 mL/min) to determine the enantiomericexcess of the product by calculating the peak areas of the twodiastereomeric derivatives formed. A 1:1 racemic sample was preparedaccording the same procedure described herein, replacing(R)-2-(2,5-difluorophenyl)pyrrolidine with(rac)-2-(2,5-difluorophenyl)pyrrolidine. The ee % of the productobtained as described above was determined to be >93%.

Preparation B

Preparation of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amineStep A: Preparation of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidine

In a pressure reaction tube was added 5-chloropyrazolo[1,5-a]pyrimidine(4.2 g, 27 mmol), (R)-2-(2,5-difluorophenyl)pyrrolidine (Preparation A;5.3 g, 29 mmol), anhydrous n-butanol (5 ml, 55 mmol), and DIEA (9.5 ml,55 mmol). The yellowish suspension was sealed and heated in an oil bath(160° C.) overnight. The reaction was cooled to ambient temperature,diluted with EtOAc (250 mL), and filtered, rinsing the solid with EtOAc.The filtrate (330 mL) was washed with water (2×150 mL), brine (100 mL),concentrated, and purified by silica chromatography, eluting with 2:1EtOAc/hexanes to give the product as a bright yellowish solid (5.6 g,68% yield).

Step B: Preparation of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)-3-nitropyrazolo[1,5-a]pyrimidine

(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidine(3.3 g, 10.99 mmol), was dissolved in 25 mL TFA at ambient temperatureto give a clear yellowish solution, then nitric acid (3.434 mL, 54.94mmol) was added drop-wise to the solution with rapid stirring. Afteraddition, the reaction mixture was stirred for another 15 minutes atambient temperature, then quenched by pouring onto ice with rapidstirring. The resulting yellowish suspension was filtered, rinsed withwater, then the solid was triturated with MeOH (50 mL, with briefsonication), and vacuum-filtered, giving the pure product as a fineoff-white powder (2.2 g, 58% yield).

Step C: Preparation of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

To a yellowish solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)-3-nitropyrazolo[1,5-a]pyrimidine(2.3 g, 6.66 mmol), in a 1:1 mixture of MeOH/DCM (30 mL/30 mL) was addedZn dust (4.36 g, 66.6 mmol) [<10 micron, Aldrich] while stirring.Saturated NH₄Cl aqueous solution (30 mL) was added drop-wise to thissuspension with rapid stirring. After NH₄Cl addition was complete, thereaction mixture was allowed to cool to ambient temperature and stirredfor another 15 minutes. The reaction was diluted with DCM (50 mL) andfiltered through a GF/F paper, rinsing the wet cake with DCM. Theorganic layer of the filtrate was separated, and the aqueous layer wasextracted with DCM (2×50 mL). The organic layers were combined, washedwith brine (100 mL), dried over Na₂SO₄, and concentrated, to provide thebasically pure product as a brownish foamy solid (2.08 g, 99% yield),which was used without further purification.

Example 1

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide

To a DCM (1.0 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 50 mg, 0.16 mmol), was added CDI (39 mg, 0.24 mmol) atambient temperature in one portion. After stirring two hours,azetidin-3-ol hydrochloride (35 mg, 0.32 mmol) [purchased from Oakwood]was added in one portion, followed by addition of DIEA (0.083 mL, 0.48mmol). After stirring for 5 minutes, the reaction was concentrated anddirectly purified by reverse-phase column chromatography, eluting with 5to 48% acetonitrile/water to yield the final product as a yellowishfoamy powder (66 mg, 100% yield). MS (apci) m/z=415.2 (M+H).

Example 1A

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamidesulfate

To a solution of(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide(44 mg, 0.11 mmol) in methanol (3 mL) at ambient temperature was addedsulfuric acid in methanol (531 μL, 0.11 mmol). The resulting solutionwas stirred for 30 minutes then concentrated to provide(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamidesulfate (38 mg, 0.074 mmol, 70% yield) as a yellow solid.

Example 1B

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamidehydrochloride

To a methanol (1 mL) solution of(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide(5.2 mg, 0.013 mmol) was added HCl as a solution is dioxane (30 μL).After 30 minutes, the reaction was concentrated to provide(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamidehydrochloride (5.7 mg, 0.013 mmol, 101% yield) as a yellow solid.

Example 2

(R)-3-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1,1-dimethylurea

To a DCM (0.8 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 30 mg, 0.095 mmol) was added CDI (31 mg, 0.19 mmol) atambient temperature in one portion. After stirring two hours,dimethylamine (0.095 mL×2 N THF, 0.19 mmol) was added in one portion.The reaction was stirred for 5 minutes, then concentrated, and theresidue was directly purified by reverse-phase column chromatography,eluting with 0 to 60% acetonitrile/water to yield the final product as ayellowish foamy powder (33 mg, 90% yield). MS (apci) m/z=387.2 (M+H).

Example 2A

(R)-3-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1,1-dimethylureahydrochloride

To a methanol (1 mL) solution of(R)-3-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1,1-dimethylurea(8.5 mg, 0.022 mmol) was added HCl as a solution is dioxane (30 μL).After 30 minutes, the reaction was concentrated to provide(R)-3-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1,1-dimethylureahydrochloride (6.7 mg, 0.016 mmol, 72% yield) as a yellow solid.

Example 3

(R)-1-tert-butyl-3-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)urea

To a DCM (0.8 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 25 mg, 0.079 mmol) was added2-isocyanato-2-methylpropane (9.4 mg, 0.095 mmol) at ambient temperaturedrop-wise, followed by addition of DIEA (0.028 mL, 0.16 mmol). Thereaction was stirred for 4 hours then concentrated, and the residue wasdirectly purified by reverse-phase column chromatography, eluting with 5to 65% acetonitrile/water to yield the final product as a pale-yellowishsolid (27 mg, 82% yield). MS (apci) m/z=415.1 (M+H).

Example 4

(R)-1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-phenylurea

To a DCM (0.8 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 25 mg, 0.079 mmol) was added isocyanatobenzene (19 mg,0.16 mmol) at ambient temperature drop-wise. The reaction was stirredfor 5 minutes then concentrated, and the residue was directly purifiedby reverse-phase column chromatography, eluting with 5 to 60%acetonitrile/water to yield the final product as a pale-yellowish solid(30 mg, 87% yield). MS (apci) m/z=435.2 (M+H).

Example 4A

(R)-1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-phenylureasulfate

To a solution of(R)-1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-phenylurea(10.1 mg, 0.0232 mmol) in methanol (0.5 mL) at ambient temperature wasadded sulfuric acid in methanol (232 μL, 0.0232 mmol). The resultingsolution was stirred for 30 minutes then concentrated to provide(R)-1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-phenylureasulfate (12 mg, 0.0225 mmol, 96.9% yield) as a yellow solid.

Example 5

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)isobutyramide

A DCM (0.5 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 20 mg, 0.063 mmol) was cooled in an ice bath, followedby addition of isobutyric anhydride (11.0 mg, 0.070 mmol) and pyridine(10 mg, 0.12 mmol) drop-wise. The reaction was allowed to warm up toambient temperature and stirred for 1 hour. The reaction mixture wasdirectly purified by reverse-phase column chromatography, eluting with 5to 60% acetonitrile/water to yield the final product as a yellowishfoamy solid (17 mg, 71%). MS (apci) m/z=386.2 (M+H).

Example 6

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-methyl-6-oxo-1,6-dihydropyridazine-3-carboxamideStep A: Preparation of(R)-5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to the method of Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step A with(R)-2-(3-fluorophenyl)pyrrolidine.

Step B: Preparation of (R)-2-(3-fluorophenyl)pyrrolidine

Prepared by the method of Preparation A, substituting2-bromo-1,4-difluorobenzene with 1-bromo-3-fluorobenzene in step A.

Step C: Preparation of(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-methyl-6-oxo-1,6-dihydropyridazine-3-carboxamide

To a mixture of(R)-5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(30 mg, 0.10 mmol), 1-methyl-6-oxo-1,6-dihydropyridazine-3-carboxylicacid (34 mg, 0.22 mmol), and HATU (84 mg, 0.22 mmol) was added 0.8 mLDMF to make a solution. After cooling in an ice bath for 10 minutes,DIEA (0.053 mL, 0.30 mmol) was added to the reaction drop-wise. Thereaction was allowed to warm up to ambient temperature and stirredovernight. The resulting fine yellowish suspension from the reactionmixture was filtered, rinsed with first DMF and then ether, to providethe final product as a yellowish solid (14.4 mg, 33% yield). MS (apci)m/z=434.2 (M+H).

Example 7

(R)—N-(5-(4,4-difluoro-2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamideSteps A1-A6: Preparation of(R)-4,4-difluoro-2-(3-fluorophenyl)-pyrrolidine Step A1. Preparation of(R)-3-(tert-butyldimethylsilyloxy)-5-(3-fluorophenyl)-3,4-dihydro-2H-pyrrole

(3-Fluorophenyl)magnesium bromide (203.2 mL×0.5 M ether, 102 mmol) wasslowly added (via syringe) to a solution of(R)-3-(tert-butyldimethylsilyloxy)-4-chlorobutanenitrile (9.5 g, 40.6mmol) in 120 mL of MTBE. The reaction was stirred for two hours and thenDME (35 ml) was slowly added over 15 minutes, followed by EtOH (23 mL).After stirring for overnight, brine and 1 M NaOH (50 mL each) were addedto the reaction. After stirring for one hour, the reaction mixture wasfiltered through Celite, rinsing the solid with EtOAc. The filtrate waswashed with 1 N NaOH and brine, filtered through Phase Separator filterpaper, and concentrated, yielding the crude product, which was carriedto the next step without further purification (12.8 g, 107% yield).

Step A2. Preparation of (3R,5R)-5-(3-fluorophenyl)pyrrolidin-3-ol

(R)-3-(tert-butyldimethylsilyloxy)-5-(3-fluorophenyl)-3,4-dihydro-2H-pyrrole(5.0 g, 17.0 mmol) was dissolved in 50 mL methanol and 10 mL AcOH andcooled to −40° C. NaBH₄ (1.6 g, 43 mmol) was slowly added in smallportions. The reaction was allowed to warm to ambient temperature. Mostof the solvent was removed by rotary evaporation. The reaction was takenup in 200 mL of EtOAc, washed with 1 N NaOH, and filtered through PhaseSeparator filter paper, and concentrated. The crude product was taken upin 20 mL of 2 N HCl in dioxane. The reaction was concentrated, taken upin 200 mL of EtOAc, washed with 1 N NaOH, filtered, and concentrated,yielding the crude product, which was carried to the next step withoutfurther purification (2.93 g, 95% yield).

Step A3. Preparation of (2R,4R)-tert-butyl2-(3-fluorophenyl)-4-hydroxypyrrolidine-1-carboxylate

To a mixture of (3R,5R)-5-(3-fluorophenyl)pyrrolidin-3-ol (3.4 g, 18.8mmol), di-tert-butyl dicarbonate (4.91 g, 22.5 mmol), and PS-DMAP (2.29g, 18.8 mmol) were added 100 mL DCM and 50 mL THF, and the reaction wasleft to stand for one week with periodic sonication treatment. Themixture was filtered, concentrated, and purified by silica columnchromatography, eluting with 2-10% MeOH/DCM to yield the pure product (4g, 76% yield).

Step A4. Preparation of (R)-tert-butyl2-(3-fluorophenyl)-4-oxopyrrolidine-1-carboxylate

(2R,4R)-tert-Butyl 2-(3-fluorophenyl)-4-hydroxypyrrolidine-1-carboxylate(1.4 g, 4.98 mmol) and Dess-Martin periodinane (2.53 g, 5.97 mmol) weremixed in 50 mL DCM and stirred at ambient temperature overnight. Forworkup, 20 mL 1N NaOH was added to reaction, and stirred for 30 minutes,followed by addition of 20 mL brine. The reaction mixture was extractedwith several portions of DCM. The combined organic extracts werefiltered through a Phase Separator filter paper, concentrated, andpurified by reverse phase chromatography, eluting with 20-70%acetonitrile/water to yield the product as yellow oil (600 mg, 43%yield.)

Step A5. Preparation of (R)-tert-butyl4,4-difluoro-2-(3-fluorophenyl)pyrrolidine-1-carboxylate

(R)-tert-butyl 2-(3-fluorophenyl)-4-oxopyrrolidine-1-carboxylate (200mg, 0.72 mmol) and Bis(2-methoxyethyl)aminosulfur trifluoride (238 mg,1.07 mmol) were mixed in 25 mL DCM and stirred at ambient temperatureovernight. For workup, 5 mL 1N NaOH was added and the reaction stirredfor 30 minutes. The reaction was filtered through Celite, rinsing withDCM. Brine (2 mL) was added to the filtrate and the mixture was filteredthrough a Biotage Phase Separator frit, washing with several portions ofDCM. The combined organic extracts were concentrated and purified byreverse phase chromatography, eluting with 20-90% acetonitrile/water toyield the product as clear oil (180 mg, 83%).

Step A6. Preparation of (R)-4,4-difluoro-2-(3-fluorophenyl)pyrrolidine

To (R)-tert-butyl4,4-difluoro-2-(3-fluorophenyl)pyrrolidine-1-carboxylate (180 mg, 0.6mmol) in a pressure reaction tube was added a solution of HCl (2 mL, 4 Ndioxane, 8 mmol), then the reaction was sealed and heated at 60° C. for4 hours. For workup, the reaction was poured into a mixture of ice and 1M NaOH, and extracted with several portions of EtOAc. The combinedorganic extracts were filtered through a Phase Separator filter paperand concentrated, yielding the final product as clear oil, which wasused in the next step without further purification.

Step B: Preparation of(R)-5-(4,4-difluoro-2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to the method of Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step 1 with(R)-4,4-difluoro-2-(3-fluorophenyl)-pyrrolidine.

Step C: Preparation of(R)—N-(5-(4,4-difluoro-2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide

To a DCM (0.7 mL) solution of(R)-5-(4,4-difluoro-2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(25 mg, 0.074 mmol), was added CDI (18 mg, 0.11 mmol) at ambienttemperature in one portion. After stirring two hours, azetidin-3-olhydrochloride (16 mg, 0.15 mmol) was added in one portion, followed byaddition of DIEA (0.039 mL, 0.22 mmol). The reaction was stirredovernight, then concentrated, and the residue was directly purified byreverse-phase column chromatography, eluting with 0 to 45%acetonitrile/water to yield the final product as a yellowish oil (15 mg,48% yield). MS (apci) m/z=433.1 (M+H).

Example 8

(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamideStep A: Preparation of(R)-5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to the method of Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step 1 with(R)-2-(2-chloro-5-fluorophenyl)pyrrolidine.

Step B: Preparation of (R)-2-(2-chloro-5-fluorophenyl)pyrrolidine

Prepared by the method of Preparation A, substituting2-bromo-1,4-difluorobenzene with 2-bromo-1-chloro-4-fluorobenzene inStep A.

Step C: Preparation of(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(30 mg, 0.090 mmol) was added CDI (29 mg, 0.18 mmol) at ambienttemperature in one portion. After stirring two hours, azetidin-3-olhydrochloride (20 mg, 0.18 mmol) was added in one portion, followed byaddition of DIEA (0.047 mL, 0.27 mmol). The reaction was stirred for 5minutes before it was concentrated and directly purified byreverse-phase column chromatography, eluting with 5 to 50%acetonitrile/water to yield the final product as a yellowish foamypowder (33 mg, 85% yield). MS (apci) m/z=431.1 (M+H).

Example 8A

(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide

To a solution of(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide(11.1 mg, 0.0258 mmol) in methanol (1 mL) at ambient temperature wasadded sulfuric acid in methanol (258 μL, 0.0258 mmol). The resultingsolution was stirred for 30 minutes then concentrated to provide(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamidesulfate (10 mg, 0.0189 mmol, 73.4% yield) as a yellow solid.

Example 9

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamideStep A: Preparation of(R)-5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to the method of Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step A with(R)-2-(3-fluorophenyl)pyrrolidine.

Step B: Preparation of(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(50 mg, 0.17 mmol) was added CDI (41 mg, 0.25 mmol) at ambienttemperature in one portion. After stirring two hours, morpholine (22 mg,0.25 mmol) was added in one portion. The reaction was stirred for 5minutes before it was concentrated and directly purified byreverse-phase column chromatography, eluting with 5 to 54%acetonitrile/water to yield the final product as a yellowish foamypowder (69 mg, 100% yield). MS (apci) m/z=411.2 (M+H).

Example 10

N-(5-(2-(3-fluorophenyl)-2-methylpyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamideStep A: Preparation of tert-butyl 4-(3-fluorophenyl)-4-oxobutylcarbamate

In a round-bottomed flask was charged tert-butyl2-oxopyrrolidine-1-carboxylate (2.2 g, 11.9 mmol) and THF (25 mL). Themixture was cooled down to −78° C. first, followed by slow addition of(3-fluorophenyl)magnesium bromide (17.8 mL, 17.8 mmol, 1.0 M solution inTHF) over 15 minutes. The mixture was stirred for 3 hours, during whichtime the bath temperature rose from −78° C. to −10° C. The reaction wasquenched by drop-wise addition of 1N HCl (2 mL) and warmed up to ambienttemperature, followed by addition of EtOAc and water. After separatingthe organic layer, the aqueous layer was extracted with EtOAc threetimes. The combined organic layers was dried over Na₂SO₄ andconcentrated to yield the product as a clear oil.

Step B: Preparation of 5-(3-fluorophenyl)-3,4-dihydro-2H-pyrrole

Crude tert-butyl 4-(3-fluorophenyl)-4-oxobutylcarbamate was dissolved in10 mL CH₂Cl₂ first, followed by addition of 10 mL 4N HCl (dioxane). Thereaction was stirred at ambient temperature for 4 hours and filtered,giving the HCl salt of the desired product as a white solid (−2 g). Toobtain the free base product, EtOAc and saturated NaHCO₃ (aq.) solutionwere added to the HCl salt of the product. After separating the organiclayer, the aqueous layer was extracted with EtOAc three times. Thecombined organic extracts was dried over Na₂SO₄ and concentrated toyield 5-(3-fluorophenyl)-3,4-dihydro-2H-pyrrole (1.46 g, 75%).

Step C: Preparation of 2-(3-fluorophenyl)-2-methylpyrrolidine

A solution of 5-(3-fluorophenyl)-3,4-dihydro-2H-pyrrole (6.1 g, 37.4mmol) in 100 mL THF was cooled to −78° C., and boron trifluoride diethyletherate (9.47 mL, 74.8 mmol) was added drop-wise over 5 minutes. Theresulting cloudy reaction mixture was stirred at −78° C. for 40 minutes.MeLi (1.6 M in diethyl ether, 46.7 mL, 74.8 mmol) was added drop-wiseover 10 minutes. The mixture was stirred at −78° C. for another 2 hours,then warmed up to ambient temperature overnight. For workup, water andEtOAc were added to the reaction mixture, and the aqueous layer wasacidified with HCl solution. After separating and discarding the organiclayer, the aqueous layer was basified with NaOH (6 N, aq.) to pH=12 andextracted twice with EtOAc. The combined organic extracts was dried overNa₂SO₄ and concentrated to get a mixture of the desired product(2-(3-fluorophenyl)-2-methylpyrrolidine) and starting material (4.3 g,1.3:1 of the desired product:starting material, 37% yield). The crudeproduct was used in the next step without any further purification.

Step D: Preparation of5-(2-(3-fluorophenyl)-2-methylpyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to the method of Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step 1 with2-(3-fluorophenyl)-2-methylpyrrolidine.

Step E: Preparation ofN-(5-(2-(3-fluorophenyl)-2-methylpyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide

To a DCM (0.7 mL) solution of5-(2-(3-fluorophenyl)-2-methylpyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(25 mg, 0.08 mmol) was added CDI (20 mg, 0.12 mmol) at ambienttemperature in one portion. After stirring one hour, azetidin-3-olhydrochloride (20 mg, 0.12 mmol) was added in one portion, followed byaddition of DIEA (0.028 mL, 0.16 mmol). The reaction was stirred for 30minutes before it was concentrated and directly purified byreverse-phase column chromatography, eluting with 0 to 60%acetonitrile/water to yield the final product as a yellowish oil (18 mg,55% yield). MS (apci) m/z=411.2 (M+H).

Example 11

(R)—N-(5-(2-(3-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamideStep A: Preparation of(R)-5-(2-(3-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to the method of Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step A with(R)-2-(3-chloro-5-fluorophenyl)pyrrolidine.

Step B: Preparation of (R)-2-(3-chloro-5-fluorophenyl)pyrrolidine

Prepared by the method of Preparation A, substituting2-bromo-1,4-difluorobenzene with 1-bromo-3-chloro-5-fluorobenzene instep A.

Step C: Preparation of(R)—N-(5-(2-(3-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide

To a DCM (0.7 mL) solution of(R)-5-(2-(3-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(20 mg, 0.06 mmol, prepared as described in the following paragraph),was added CDI (20 mg, 0.12 mmol) at ambient temperature in one portion.After stirring two hours, azetidin-3-ol hydrochloride (20 mg, 0.18 mmol)was added in one portion, followed by addition of DIEA (0.032 mL, 0.18mmol). The reaction was stirred overnight before it was concentrated anddirectly purified by reverse-phase column chromatography, eluting with 0to 60% acetonitrile/water to yield the final product as a solid (29 mg,74% yield). MS (apci) m/z=431.2 (M+H).

Example 12

(R)—N-(5-(2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamideStep A: Preparation of(R)-5-(2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to the method of Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step A with(R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidine.

Step B: Preparation of (R)-2-(3-chloro-5-fluorophenyl)pyrrolidine

Prepared by the method of Preparation A, substituting2-bromo-1,4-difluorobenzene with2-bromo-1-(difluoromethyl)-4-fluorobenzene in step A.

Step C: Preparation of (R)—N-(5-(2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide

To a DCM (0.6 mL) solution of(R)-5-(2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(10 mg, 0.028 mmol, prepared as described in the following paragraph),was added CDI (9 mg, 0.056 mmol) at ambient temperature in one portion.After stirring two hours, azetidin-3-ol hydrochloride (6 mg, 0.056 mmol)was added in one portion, followed by addition of DIEA (0.015 mL, 0.084mmol). The reaction was stirred overnight before it was concentrated anddirectly purified by reverse-phase column chromatography, eluting with 0to 50% acetonitrile/water to yield the final product as a solid. MS(apci) m/z=447.2 (M+H).

Example 13

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 30 mg, 0.095 mmol) was added CDI (31 mg, 0.19 mmol) atambient temperature in one portion. After stirring two hours, morpholine(17 mg, 0.19 mmol) was added in one portion. The reaction was stirredfor 5 minutes before it was concentrated and directly purified byreverse-phase column chromatography, eluting with 5 to 55%acetonitrile/water to yield the final product as a yellowish foamypowder (37 mg, 91% yield). MS (apci) m/z=429.2 (M+H).

Example 14

(S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 30 mg, 0.095 mmol) was added CDI (31 mg, 0.19 mmol) atambient temperature in one portion. After stirring two hours,(S)-pyrrolidin-3-ol (17 mg, 0.19 mmol) [purchased from Suven LifeSciences] was added in one portion. The reaction was stirred for 5minutes before it was concentrated and directly purified byreverse-phase column chromatography, cluting with 0 to 50%acetonitrile/water to yield the final product as a yellowish foamypowder (30 mg, 74% yield). MS (apci) m/z=429.2 (M+H).

Example 14A

(S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamidesulfate

To a solution of(S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide(4.5 mg, 0.011 mmol) in methanol (1 mL) at ambient temperature was addedsulfuric acid in MeOH (105 μL, 0.011 mmol). The resulting solution wasstirred for 30 minutes then concentrated to provide(S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamidesulfate (5.2 mg, 0.0099 mmol, 94% yield) as a yellow solid.

Example 15

(3R,4R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3,4-dihydroxypyrrolidine-1-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 26 mg, 0.08 mmol) was added CDI (27 mg, 0.16 mmol) atambient temperature in one portion. After stirring two hours,(3R,4R)-pyrrolidine-3,4-diol (17.3 mg, 0.16 mmol) [obtained from benzylde-protection of commercially available(3R,4R)-1-benzylpyrrolidine-3,4-diol] was added in one portion. A fewdrops of DMSO were added to obtain a clear reaction solution. Thereaction was stirred for 5 minutes before it was concentrated anddirectly purified by reverse-phase column chromatography, eluting with 0to 45% acetonitrile/water to yield the final product as a yellowishfoamy powder (27 mg, 74% yield). MS (apci) m/z=445.2 (M+H).

Example 16

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methoxyazetidine-1-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 30 mg, 0.095 mmol) was added CDI (31 mg, 0.19 mmol) atambient temperature in one portion. After stirring two hours,3-methoxyazetidine 2,2,2-trifluoroacetate (38 mg, 0.19 mmol) [obtainedfrom N-de-protection of commercially available tert-butyl3-methoxyazetidine-1-carboxylate using TFA in DCM] was added in oneportion, followed by addition of DIEA (0.050 mL, 0.29 mmol). Thereaction was stirred for 5 minutes before it was concentrated anddirectly purified by reverse-phase column chromatography, cluting with 0to 55% acetonitrile/water to yield the final product as a yellowishfoamy powder (34 mg, 83% yield). MS (apci) m/z=429.2 (M+H).

Example 16A

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methoxyazetidine-1-carboxamidesulfate

To a solution of(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methoxyazetidine-1-carboxamide(6.2 mg, 0.014 mmol) in methanol (1 mL) at ambient temperature was addedsulfuric acid in methanol (145 μL, 0.014 mmol). The resulting solutionwas stirred for 30 minutes then concentrated to provide(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methoxyazetidine-1-carboxamidesulfate (7.2 mg, 0.014 mmol, 94% yield) as a yellow solid.

Example 17

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-3-methylazetidine-1-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 30 mg, 0.095 mmol) was added CDI (31 mg, 0.19 mmol) atambient temperature in one portion. After stirring two hours,3-methoxyazetidine 3-methylazetidin-3-ol hydrochloride (26 mg, 0.19mmol) [obtained from N-de-protection of commercially available1-benzhydryl-3-methylazetidin-3-ol under hydrogenation conditionsfacilitated by Pd(OH)₂ in EtOH and 1% TFA] was added in one portion,followed by addition of DIEA (0.050 mL, 0.29 mmol). The reaction wasstirred for 5 minutes before it was concentrated and directly purifiedby reverse-phase column chromatography, eluting with 0 to 50%acetonitrile/water to yield the final product as a yellowish foamypowder (27 mg, 66% yield). MS (apci) m/z=429.2 (M+H).

Example 17A

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-3-methylazetidine-1-carboxamidesulfate

To a solution of(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-3-methylazetidine-1-carboxamide(3.1 mg, 0.0072 mmol) in methanol (1 mL) at ambient temperature wasadded sulfuric acid in methanol (145 μL, 0.014 mmol). The resultingsolution was stirred for 30 minutes then concentrated to provide(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-3-methylazetidine-1-carboxamidesulfate (3.3 mg, 0.0063 mmol, 87% yield) as a yellow solid.

Example 17B

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-3-methylazetidine-1-carboxamidehydrochloride

To a methanol (1 mL) solution of(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-3-methylazetidine-1-carboxamide(10.2 mg, 0.0238 mmol) was added HCl as a solution is dioxane (30 μL).After 30 minutes, the reaction was concentrated to provide(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-3-methylazetidine-1-carboxamidehydrochloride (8.3 mg, 0.0179 mmol, 75.0% yield) as a yellow solid.

Example 18

(R)-1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-(4-fluorophenyl)urea

To a DCM (0.8 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amino(Preparation B; 25 mg, 0.079 mmol) was added1-fluoro-4-isocyanatobenzene (13 mg, 0.095 mmol) at ambient temperaturedrop-wise, followed by addition of DIEA (0.028 mL, 0.16 mmol). Thereaction was stirred for 90 minutes before it was concentrated anddirectly purified by column chromatography on silica, eluting with 3:1EtOAc/hexanes to yield the final product as a solid (30 mg, 84% yield).MS (apci) m/z=453.2 (M+H).

Example 19

(R)-1-(4-chlorophenyl)-3-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)urea

Prepared by the method as described in Example 18, substituting1-fluoro-4-isocyanatobenzene with 1-chloro-4-isocyanatobenzene, givingthe final product as a fine white solid (33 mg, 89%). MS (apci)m/z=469.1 (M+H).

Example 20

(R)-1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-(4-methoxyphenyl)urea

Prepared by the method as described in Example 18, substituting1-fluoro-4-isocyanatobenzene with 1-methoxy-4-isocyanatobenzene, andeluting with first 4:1 EtOAc/hexanes and then 100% EtOAc during silicacolumn chromatography purification step, giving the final product as afine white solid (34 mg, 92%). MS (apci) m/z=465.2 (M+H).

Example 21

(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methoxyazetidine-1-carboxamideStep A: Preparation of(R)-5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to the method of Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step A with(R)-2-(2-chloro-5-fluorophenyl)pyrrolidine.

Step B: Preparation of(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methoxyazetidine-1-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(30 mg, 0.090 mmol) was added CDI (29 mg, 0.18 mmol) at ambienttemperature in one portion. After stirring for two hours,3-methoxyazetidine 2,2,2-trifluoroacetate (36 mg, 0.18 mmol) [obtainedfrom N-de-protection of commercially available tert-butyl3-methoxyazetidine-1-carboxylate using TFA in DCM] was added in oneportion, followed by addition of DIEA (0.047 mL, 0.27 mmol). Thereaction was stirred for 5 minutes before it was concentrated anddirectly purified by reverse-phase column chromatography, eluting with 5to 60% acetonitrile/water to yield the final product as a yellowishfoamy powder (36 mg, 89% yield). MS (apci) m/z=445.2 (M+H).

Example 22

(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-3-methylazetidine-1-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Example 8, Step A; 22 mg, 0.066 mmol) was added CDI (22 mg, 0.13 mmol)at ambient temperature in one portion. After stirring two hours,3-methoxyazetidine 3-methylazetidin-3-ol hydrochloride (18 mg, 0.13mmol) was added in one portion, followed by addition of DIEA (0.035 mL,0.20 mmol). The reaction was stirred for 5 minutes before it wasconcentrated and directly purified by reverse-phase columnchromatography, eluting with 5 to 50% acetonitrile/water to yield thefinal product as a yellowish foamy powder (21 mg, 71% yield). MS (apci)m/z=445.2 (M+H).

Example 23

(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide

Prepared according to the method of Example 22, replacing(R)-5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-aminewith morpholine to yield the product as a yellowish foamy powder (26 mg,76% yield). MS (apci) m/z=445.1 (M+H).

Example 24

(S)-tert-butyl4-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-2-methylpiperazine-1-carboxylate

Prepared according to the method of Example 22, replacing(R)-5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-aminewith (S)-tert-butyl 2-methylpiperazine-1-carboxylate to yield theproduct as a yellowish foamy powder (47 mg, 80% yield). MS (apci)m/z=558.1 (M+H).

Example 25

(S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpiperazine-1-carboxamidehydrochloride

To (S)-tert-butyl4-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-2-methylpiperazine-1-carboxylate(Example 24; 47 mg, 0.084 mmol), was added 1 mL 4 N HCl (dioxane)solution and stirred at ambient temperature for 10 minutes. The reactionwas concentrated, treated with ether, and filtered, giving the finalproduct HCl salt as a fine beige powder. MS (apci) m/z=458.1 (M+H).

Example 26

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-isopropylpiperazine-1-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 30 mg, 0.095 mmol) was added CDI (31 mg, 0.19 mmol) atambient temperature in one portion. After stirring two hours,1-isopropylpiperazine (24 mg, 0.19 mmol) was added in one portion. Thereaction was stirred for 5 minutes before it was concentrated anddirectly purified by reverse-phase column chromatography, eluting with 5to 45% acetonitrile/water to yield the final product as a yellowishfoamy powder (40 mg, 90% yield). MS (apci) m/z=470.1 (M+H).

Example 27

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-ethylpiperazine-1-carboxamide

Prepared by the method as described in Example 26, substituting1-isopropylpiperazine with 1-ethylpiperazine, giving the final productas a yellowish solid (40 mg, 92%). MS (apci) m/z=456.1 (M+H).

Example 28

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-methylpiperazine-1-carboxamide

Prepared by the method as described in Example 26, substituting1-isopropylpiperazine with 1-methylpiperazine, giving the final productas a yellowish solid (38 mg, 90%). MS (apci) m/z=442.2 (M+H).

Example 28A

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-methylpiperazine-1-carboxamidehydrochloride

To a methanol (1 mL) solution of(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-methylpiperazine-1-carboxamidewas added HCl as a solution is dioxane (30 μL). After 30 minutes, thereaction was concentrated to provide(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-methylpiperazine-1-carboxamidehydrochloride as a yellow solid.

Example 29

N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3,5-dimethylpiperazine-1-carboxamide

Prepared by the method as described in Example 26, substituting1-isopropylpiperazine with 2,6-dimethylpiperazine [predominantly cis,Aldrich], giving the final product as a yellowish solid (34 mg, 78%). MS(apci) m/z=456.2 (M+H).

Example 30

(S)-tert-butyl4-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-2-methylpiperazine-1-carboxylate

Prepared by the method as described in Example 26, substituting1-isopropylpiperazine with (S)-tert-butyl2-methylpiperazine-1-carboxylate, giving the final product as ayellowish solid (47 mg, 90%). MS (apci) m/z=542.2 (M+H).

Example 31

(S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpiperazine-1-carboxamidehydrochloride

To (S)-tert-butyl4-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-2-methylpiperazine-1-carboxylate(Example 30; 47 mg, 0.087 mmol), was added 1 mL 4 N HCl (dioxane)solution and stirred at ambient temperature for 1 hour. The reaction wasconcentrated, treated with ether, and filtered, giving the final productHCl salt as a fine yellowish powder. MS (apci) m/z=442.2 (M+H).

Example 32

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxyazetidine-1-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Example 6, Step A; 50 mg, 0.17 mmol) was added CDI (41 mg, 0.25 mmol)at ambient temperature in one portion. After stirring two hours,azetidin-3-ol hydrochloride (28 mg, 0.25 mmol) was added in one portion,followed by addition of DIEA (0.059 mL, 0.34 mmol). The reaction wasstirred for 5 minutes before it was concentrated and directly purifiedby reverse-phase column chromatography, eluting with 5 to 55%acetonitrile/water to yield the final product as a yellowish foamypowder (64 mg, 96% yield). MS (apci) m/z=397.2 (M+H).

Example 33

(R)-methyl1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)cyclopropanecarboxylate

To a mixture of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 43 mg, 0.14 mmol),1-(methoxycarbonyl)cyclopropanecarboxylic acid (24 mg, 0.16 mmol), andHATU (62 mg, 0.16 mmol) was added 0.7 mL DMF to make a solution. Aftercooling in an ice bath for 10 minutes, DIEA (0.053 mL, 0.30 mmol) wasadded to the reaction drop-wise. The reaction was allowed to warm up toambient temperature and stirred for 10 minutes. The reaction mixture wasdiluted with EtOAc (15 mL), washed with water, brine (5 mL each),concentrated, and purified by reverse-phase column chromatography,eluting with 5 to 72% acetonitrile/water to yield the final product as ayellowish foamy powder (36 mg, 60% yield). MS (apci) m/z=442.2 (M+H).

Example 34

(R)-1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)cyclopropanecarboxylicacid

(R)-methyl1-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)cyclopropanecarboxylate(Example 33; 24 mg, 0.054 mmol), was dissolved in a mixture solvent ofTHF/MeOH/water (0.3/0.3/0.2 mL), followed by addition of lithiumhydroxide monohydrate (6 mg, 0.14 mmol). After stirring at ambienttemperature for five hours, the reaction mixture was diluted with water(15 mL), acidified with 1 N HCl (aq.) to pH˜3, and filtered, giving thefinal product as a fine white solid (19 mg, 82% yield). MS (apci)m/z=428.2 (M+H).

Example 35

(S)—N-(5-((R)-2-(3-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

To a DCM (0.6 mL) solution of(R)-5-(2-(3-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Example 11, Step A; 20 mg, 0.06 mmol), was added CDI (20 mg, 0.12 mmol)at ambient temperature in one portion. After stirring two hours,(S)-pyrrolidin-3-ol (16 mg, 0.18 mmol) was added in one portion. Thereaction was stirred overnight before it was concentrated and directlypurified by reverse-phase column chromatography, eluting with 0 to 60%acetonitrile/water to yield the final product as a solid (50 mg, 83%yield). MS (apci) m/z=445.2 (M+H).

Example 36

(R)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamideStep A: Preparation of(R)-5-(2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to the method of Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step 1 with(R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidine.

Step B: Preparation of(R)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

To a DCM (0.6 mL) solution of(R)-5-(2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(10 mg, 0.028 mmol, prepared as described in the following paragraph),was added CDT (9 mg, 0.056 mmol) at ambient temperature in one portion.After stirring two hours, (S)-pyrrolidin-3-ol (8 mg, 0.084 mmol) wasadded in one portion. The reaction was stirred overnight, thenconcentrated and directly purified by reverse-phase columnchromatography, eluting with 0 to 50% acetonitrile/water to yield thefinal product as a solid (9 mg, 69%). MS (apci) m/z=461.2 (M+H).

Example 37

(S)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

Prepared by the method as described in Example 36, substituting(S)-pyrrolidin-3-ol with (R)-pyrrolidin-3-ol, giving the final productas a solid (12 mg, 89%). MS (apci) m/z=461.2 (M+H).

Example 38

(R)—N-(5-(2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-hydroxypiperidine-1-carboxamide

Prepared by the method as described in Example 36, substituting(S)-pyrrolidin-3-ol with piperidin-4-ol, giving the final product as asolid (11 mg, 80%). MS (apci) m/z=475.2 (M+H).

Example 39

(R)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide

Prepared by the method as described in Example 36, substituting(S)-pyrrolidin-3-ol with (R)-piperidin-3-ol hydrochloride (followed byaddition of 3 equivalents of DIEA), giving the final product as a solid(10 mg, 74%). MS (apci) m/z=475.2 (M+H).

Example 40

(S)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide

Prepared by the method as described in Example 36, substituting(S)-pyrrolidin-3-ol with (S)-piperidin-3-ol hydrochloride (followed byaddition of 3 equivalents of DIEA), giving the final product as a solid(11 mg, 80%). MS (apci) m/z=475.2 (M+H).

Example 41

(R)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(10 mg, 0.030 mmol, prepared as described in Example 8) was added CDI(10 mg, 0.06 mmol) at ambient temperature in one portion. After stirringtwo hours, (S)-pyrrolidin-3-ol (5 mg, 0.06 mmol) was added in oneportion. The reaction was stirred at ambient temperature for 20 hoursbefore it was concentrated and directly purified by reverse-phase columnchromatography, eluting with 5 to 50% acetonitrile/water to yield thefinal product as a solid (9 mg, 67% yield). MS (apci) m/z=445.2 (M+H).

Example 42

(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-hydroxypiperidine-1-carboxamide

Prepared by the method as described in Example 41, substituting(S)-pyrrolidin-3-ol with piperidin-4-ol, giving the final product as asolid (8 mg, 60%). MS (apci) m/z=459.2 (M+H).

Example 43

(R)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide

Prepared by the method as described in Example 41, substituting(S)-pyrrolidin-3-ol with (R)-piperidin-3-ol hydrochloride (followed byaddition of 3 equivalents of DIEA), giving the final product as a solid(9.4 mg, 69%). MS (apci) m/z=459.1 (M+H).

Example 44

(S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide

Prepared by the method as described in Example 41, substituting(S)-pyrrolidin-3-ol with (S)-piperidin-3-ol hydrochloride (followed byaddition of 3 equivalents of DIEA), giving the final product as a solid(9.3 mg, 68%). MS (apci) m/z=459.2 (M+H).

Example 45

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)pivalamide

A DCM (0.5 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amino(Preparation B; 20 mg, 0.063 mmol) was cooled in an ice bath, followedby addition of pivalic anhydride (26 mg, 0.14 mmol) and pyridine (12 mg,0.14 mmol) drop-wise. The reaction was allowed to warm up to ambienttemperature and stirred for 1 hour. The reaction mixture was directlypurified by reverse-phase column chromatography, eluting with 5 to 65%acetonitrile/water to yield the final product as a yellowish foamy solid(19 mg, 75%). MS (apci) m/z=400.2 (M+H).

Example 46

(R)-tert-butyl3-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)azetidine-1-carboxylate

To a mixture of(R)-5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Example 8, Step A; 20 mg, 0.06 mmol),1-(tert-butoxycarbonyl)azetidine-3-carboxylic acid (15 mg, 0.072 mmol),and HATU (28 mg, 0.072 mmol) was added 0.6 mL acetonitrile to make asolution. After cooling in an ice bath for 10 minutes, DIEA (0.032 mL,0.18 mmol) was added to the reaction drop-wise. The reaction was allowedto warm up to ambient temperature and stirred overnight. The reactionmixture was directly purified by reverse-phase column chromatography,eluting with 5 to 70% acetonitrile/water to yield the final product asan off-white solid (19 mg, 61% yield). MS (apci) m/z=515.0 (M+H).

Example 47

(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)azetidine-3-carboxamidetrifluoroacetate

To (R)-tert-butyl3-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)azetidine-1-carboxylate(Example 46; 17 mg, 0.033 mmol), was added 0.5 mL 50% TFA solution inDCM and stirred at ambient temperature for 10 minutes. The reaction wasconcentrated, treated with ether, and filtered, giving the final product(TFA salt) as a fine beige powder (12 mg, 88% yield). MS (apci)m/z=415.2 (M+H).

Example 48

(R)-tert-butyl4-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-4-methylpiperidine-1-carboxylate

To a mixture of(R)-5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Example 8, Step A; 25 mg, 0.075 mmol),1-(tert-butoxycarbonyl)-4-methylpiperidine-4-carboxylic acid (22 mg,0.090 mmol), and HATU (34 mg, 0.090 mmol) was added 0.6 mL DMF to make asolution. After cooling in an ice bath for 10 minutes, DIEA (0.039 mL,0.23 mmol) was added to the reaction dropwise. The reaction was allowedto warm up to ambient temperature and stirred overnight. The reactionmixture was directly purified by reverse-phase column chromatography,eluting with 5 to 80% acetonitrile/water to yield the final product as ayellowish powder (28 mg, 67% yield). MS (apci) m/z=557.1 (M+H).

Example 49

(R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-methylpiperidine-4-carboxamidehydrochloride

To (R)-tert-butyl4-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-4-methylpiperidine-1-carboxylate(Example 48; 28 mg, 0.05 mmol), was added 1 mL 4 N HCl solution indioxane and stirred at ambient temperature for 10 minutes. The reactionwas concentrated, treated with ether, and filtered, giving the finalproduct (HCl salt) as a fine beige powder. MS (apci) m/z=457.1 (M+H).

Example 50

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-hydroxy-2-methylpropanamide

To a mixture of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 25 mg, 0.079 mmol), 2-hydroxy-2-methylpropanoic acid (10mg, 0.095 mmol), and HATU (36 mg, 0.095 mmol) was added 0.6 mLacetonitrile to make a solution. After cooling in an ice bath for 10minutes, DIEA (0.041 mL, 0.24 mmol) was added to the reaction drop-wise.The reaction was allowed to warm up to ambient temperature and stirredovernight. The reaction mixture was concentrated, re-dissolved inmethanol, and purified by reverse-phase column chromatography, elutingwith 5 to 55% acetonitrile/water to yield the final product as anoff-white solid (21 mg, 66% yield). MS (apci) m/z=402.2 (M+H).

Example 51

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-(trifluoromethyl)cyclopropanecarboxamide

To a mixture of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 25 mg, 0.079 mmol),1-(trifluoromethyl)cyclopropanecarboxylic acid (15 mg, 0.095 mmol), andHATU (36 mg, 0.095 mmol) was added 0.6 mL DMF to make a solution. Aftercooling in an ice bath for 10 minutes, DIEA (0.041 mL, 0.24 mmol) wasadded to the reaction drop-wise. The reaction was allowed to warm up toambient temperature and stirred overnight. The reaction mixture wasdiluted with EtOAc (15 mL), washed with water and brine (5 mL each),concentrated, and purified by reverse-phase column chromatography,eluting with 5 to 72% acetonitrile/water to yield the final product as abeige solid (23 mg, 63% yield). MS (apci) m/z=452.2 (M+H).

Example 52

(R)-1-cyano-N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)cyclopropanecarboxamide

Prepared by the method as described in Example 51, substituting1-(trifluoromethyl)cyclopropanecarboxylic acid with1-cyanocyclopropanecarboxylic acid, to provide the final product as awhite solid (18 mg, 56% yield). MS (apci) m/z=409.2 (M+H).

Example 53

(R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-methylpyrrolidine-2-carboxamide

To a mixture of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amino(Preparation B; 25 mg, 0.079 mmol),(R)-1-(tert-butoxycarbonyl)-2-methylpyrrolidine-2-carboxylic acid (22mg, 0.095 mmol), and HATU (36 mg, 0.095 mmol) was added 0.6 mL DMF tomake a solution. After cooling in an ice bath for 10 minutes, DIEA(0.041 mL, 0.24 mmol) was added to the reaction drop-wise. The reactionwas allowed to warm up to ambient temperature and stirred overnight. Thereaction mixture was diluted with EtOAc (15 mL), washed with water andbrine (5 mL each), concentrated, and purified by reverse-phase columnchromatography, eluting with 5 to 68% acetonitrile/water to yield theN-Boc-protected product, (R)-tert-butyl2-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-2-methylpyrrolidine-1-carboxylate,as a beige solid (32 mg, 73% yield). The dc-protection was carried outby adding 1 mL 4 N HCl solution in dioxane to the above protectedproduct. After 1 hour at ambient temperature, the reaction mixture wasconcentrated, treated with ether (1 mL), and filtered, giving the finalproduct as an off-white solid. MS (apci) m/z=427.2 (M+H).

Example 54

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-fluoro-2-methylpropanamide

Prepared by the method as described in Example 51, substituting1-(trifluoromethyl)-cyclopropane-carboxylic acid with2-fluoro-2-methylpropanoic acid, to provide the final product as apale-yellowish solid (25 mg, 77% yield). MS (apci) m/z=404.2 (M+H).

Example 55

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-(isopropylamino)thiazole-4-carboxamide

Prepared by the method as described in Example 51, substituting1-(trifluoromethyl)-cyclopropane-carboxylic acid with2-(isopropylamino)thiazole-4-carboxylic acid hydrobromide, to providethe final product as a beige solid (34 mg, 89% yield). MS (apci)m/z=484.2 (M+H).

Example 56

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-methyl-2-(1H-1,2,4-triazol-1-yl)propanamide

Prepared by the method as described in Example 51, substituting1-(trifluoromethyl)-cyclopropane-carboxylic acid with2-methyl-2-(1H-1,2,4-triazol-1-yl)propanoic acid, to provide the finalproduct as a pale-yellowish solid (26 mg, 72% yield). MS (apci)m/z=453.1 (M+H).

Example 57

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)pyrazine-2-carboxamide

To a mixture of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 25 mg, 0.079 mmol), pyrazine-2-carboxylic acid (12 mg,0.095 mmol), and HATU (36 mg, 0.095 mmol) was added 0.6 mL DMF to make asolution. After cooling in an ice bath for 10 minutes, DIEA (0.041 mL,0.24 mmol) was added to the reaction drop-wise. The reaction was allowedto warm up to ambient temperature and stirred for 10 minutes. Thereaction mixture was diluted with EtOAc (15 mL), washed with water andbrine (5 mL each), concentrated, and purified by reverse-phase columnchromatography, eluting with 5 to 65% acetonitrile/water to yield thefinal product as a yellowish solid (31 mg, 93% yield). MS (apci)m/z=422.2 (M+H).

Example 58

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-5-methylpyrazine-2-carboxamide

Prepared by the method as described in Example 57, substitutingpyrazine-2-carboxylic acid with 5-methylpyrazine-2-carboxylic acid, toprovide the final product as a yellowish solid (9 mg, 26% yield). MS(apci) m/z=436.2 (M+H).

Example 59

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)picolinamide

Prepared by the method as described in Example 57, substitutingpyrazine-2-carboxylic acid with picolinic acid, to provide the finalproduct as a yellowish solid (31 mg, 93% yield). MS (apci) m/z=421.2(M+H).

Example 60

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-6-methylpicolinamide

Prepared by the method as described in Example 57, substitutingpyrazine-2-carboxylic acid with 6-methylpicolinic acid, to provide thefinal product as a yellowish solid (30 mg, 87% yield). MS (apci)m/z=435.2 (M+H).

Example 60A

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-6-methylpicolinamidehydrochloride

To a methanol (1 mL) solution of(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpicolinamide(10.3 mg, 0.0237 mmol) was added HCl as a solution is dioxane (30 μL).After 30 minutes, the reaction was concentrated to provide(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpicolinamidehydrochloride as a yellow solid.

Example 61

(R)-5-chloro-N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)picolinamide

Prepared by the method as described in Example 57, substitutingpyrazine-2-carboxylic acid with 5-chloropicolinic acid, to provide thefinal product as a yellowish solid (24 mg, 67% yield). MS (apci)m/z=455.2 (M+H).

Example 62

(R)-4-chloro-N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)picolinamide

Prepared by the method as described in Example 57, substitutingpyrazine-2-carboxylic acid with 4-chloropicolinic acid, to provide thefinal product as a beige solid (30 mg, 83% yield). MS (apci) m/z=455.2(M+H).

Example 63

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpicolinamide

Prepared by the method as described in Example 57, substitutingpyrazine-2-carboxylic acid with 3-methylpicolinic acid, to provide thefinal product as a beige solid (33 mg, 96% yield). MS (apci) m/z=435.2(M+H).

Example 64

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxy-2,2-dimethylpropanamide

Prepared by the method as described in Example 57, substitutingpyrazine-2-carboxylic acid with 3-hydroxy-2,2-dimethylpropanoic acid, toprovide the final product as a pale-yellowish solid (22 mg, 66% yield).MS (apci) m/z=416.2 (M+H).

Example 65

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-hydroxycyclopropanecarboxamide

Prepared by the method as described in Example 57, substitutingpyrazine-2-carboxylic acid with 1-hydroxycyclopropanecarboxylic acid, toprovide the final product as a beige solid (6 mg, 16% yield). MS (apci)m/z=400.2 (M+H).

Example 66

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-methyl-2-(methylamino)propanamide

Prepared by the method as described in Example 57, substitutingpyrazine-2-carboxylic acid with 2-methyl-2-(methylamino)propanoic acidhydrochloride, to provide the final product as a solid (2 mg, 6% yield).MS (apci) m/z=415.1 (M+H).

Example 67

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)pyrimidine-2-carboxamide

To a mixture of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 25 mg, 0.079 mmol), pyrimidine-2-carboxylic acid (12 mg,0.095 mmol), and HATU (36 mg, 0.095 mmol) was added 0.6 mL DMF. A fewdrops of DMSO were added to obtain a solution. After cooling in an icebath for 10 minutes, DIEA (0.041 mL, 0.24 mmol) was added to thereaction drop-wise. The reaction was allowed to warm up to ambienttemperature and stirred for one hour, then at 80° C. for 16 hours.Reaction did not reach completion before workup. The reaction mixturewas diluted with EtOAc (15 mL), washed with water and brine (5 mL each),concentrated, and purified by reverse-phase column chromatography,eluting with 5 to 60% acetonitrile/water to yield the final product as alight yellowish solid (3 mg, 9% yield). MS (apci) m/z=422.2 (M+H).

Example 68

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)picolinamide

To a mixture of(R)-5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amino(Example 6, Step A; 30 mg, 0.1 mmol), picolinic acid (15 mg, 0.12 mmol),and HATU (46 mg, 0.12 mmol) was added 0.7 mL DMF to make a solution.After cooling in an ice bath for 10 minutes, DIEA (0.053 mL, 0.3 mmol)was added to the reaction drop-wise. The reaction was allowed to warm upto ambient temperature and stirred for 10 minutes. The reaction mixturewas diluted with EtOAc (15 mL), washed with water and brine (5 mL each),concentrated, and purified by reverse-phase column chromatography,eluting with 5 to 70% acetonitrile/water to yield the final product as ayellowish solid (35 mg, 86% yield). MS (apci) m/z=403.2 (M+H).

Example 69

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpicolinamide

Prepared by the method as described in Example 68, substitutingpicolinic acid with 3-methylpicolinic acid, to provide the final productas a solid (35 mg, 83% yield). MS (apci) m/z=417.2 (M+H).

Example 70

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-methyl-2-oxo-1,2-dihydropyridine-4-carboxamide

Prepared by the method as described in Example 68, substitutingpicolinic acid with 1-methyl-2-oxo-1,2-dihydropyridine-4-carboxylicacid, to provide the final product as a yellowish solid (18 mg, 41%yield). MS (apci) m/z=433.2 (M+H).

Example 71

(R)-6-chloro-N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)picolinamide

Prepared by the method as described in Example 68, substituting(R)-5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-aminewith(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B), and substituting picolinic acid with 6-chloropicolinicacid, to provide the final product as a yellowish solid (9.1 mg, 31%yield). MS (apci) m/z=455.2 (M+H).

Example 72

(R)-4-(ethylsulfonamido)-N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)benzamide

Prepared by the method as described in Example 68, substitutingpicolinic acid with 4-(ethylsulfonamido)benzoic acid, to provide thefinal product as a yellowish solid (32 mg, 62% yield). MS (apci)m/z=509.2 (M+H).

Example 73

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-methyl-1H-pyrazole-3-carboxamide

Prepared by the method as described in Example 68, substitutingpicolinic acid with 1-methyl-1H-pyrazolo-3-carboxylic acid, to providethe final product as a yellowish solid (32 mg, 78% yield). MS (apci)m/z=406.3 (M+H).

Example 74

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1H-pyrazolo-3-carboxamide

Prepared by the method as described in Example 68, substitutingpicolinic acid with 1H-pyrazole-3-carboxylic acid, to provide the finalproduct as a yellowish solid (14 mg, 35% yield). MS (apci) m/z=392.2(M+H).

Example 75

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-6-methoxypicolinamide

Prepared by the method as described in Example 68, substitutingpicolinic acid with 6-methoxypicolinic acid, to provide the finalproduct as a yellowish solid (28 mg, 64% yield). MS (apci) m/z=433.2(M+H).

Example 75A

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-6-methoxypicolinamidehydrochloride

To a methanol (1 mL) solution of(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-6-methoxypicolinamide(10.1 mg, 0.0234 mmol) was added HCl as a solution is dioxane (30 μL).After 30 minutes, the reaction was concentrated to provide(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-6-methoxypicolinamidehydrochloride as a yellow solid.

Example 76

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)nicotinamide

To a mixture of(R)-5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Example 6, Step A; 30 mg, 0.1 mmol), nicotinic acid (25 mg, 0.2 mmol),and HATU (77 mg, 0.2 mmol) was added 0.7 mL DMF to make a solution.After cooling in an ice bath for 10 minutes, DIEA (0.053 mL, 0.3 mmol)was added to the reaction drop-wise. The reaction was allowed to warm upto ambient temperature and stirred for 3 hours. The reaction mixture wasdiluted with EtOAc (15 mL), washed with water and brine (5 mL each),concentrated, and purified by reverse-phase column chromatography,eluting with 5 to 57% acetonitrile/water to yield the final product as ayellowish solid (30 mg, 74% yield). MS (apci) m/z=403.2 (M+H).

Example 77

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)isonicotinamide

Prepared by the method as described in Example 76, substitutingnicotinic acid with isonicotinic acid, to provide the final product as ayellowish solid (20 mg, 49% yield). MS (apci) m/z=403.2 (M+H).

Example 78

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-6-methylnicotinamide

Prepared by the method as described in Example 76, substitutingnicotinic acid with 6-methylnicotinic acid, to provide the final productas a yellowish solid (27 mg, 64% yield). MS (apci) m/z=417.2 (M+H).

Example 79

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-methoxynicotinamide

Prepared by the method as described in Example 76, substitutingnicotinic acid with 2-methoxynicotinic acid, to provide the finalproduct as a yellowish solid (32 mg, 73% yield). MS (apci) m/z=433.2(M+H).

Example 80

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylisonicotinamide

Prepared by the method as described in Example 76, substitutingnicotinic acid with 3-methylisonicotinic acid, to provide the finalproduct as a yellowish solid (22 mg, 52% yield). MS (apci) m/z=417.2(M+H).

Example 81

(S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

To a DCM (0.8 mL) solution of(R)-5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Example 8, Step A; 30 mg, 0.09 mmol) was added CDI (29 mg, 0.18 mmol)at ambient temperature in one portion. After stirring two hours,(S)-pyrrolidin-3-ol (15.8 mg, 0.181 mmol) was added in one portion. Thereaction was stirred for 5 minutes before it was concentrated anddirectly purified by reverse-phase column chromatography, eluting with 5to 53% acetonitrile/water to yield the final product as a yellowishfoamy powder (33 mg, 81% yield). MS (apci) m/z=445.2 (M+H).

Example 82

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-5-methylpyrazine-2-carboxamide

To a mixture of(R)-5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Example 6, Step A; 50 mg, 0.17 mmol, prepared as described in aprevious example), 5-methylpyrazine-2-carboxylic acid (46 mg, 0.34mmol), and HATU (128 mg, 0.34 mmol) was added 0.7 mL DMF to make asolution. After cooling in an ice bath for 10 minutes, DIEA (0.088 mL,0.5 mmol) was added to the reaction drop-wise. The reaction was allowedto warm up to ambient temperature and stirred for 2 hours. The reactionmixture was directly filtered, rinsing with acetonitrile and then withether, to provide the final product as a beige solid (44 mg, 63% yield).MS (apci) m/z=418.2 (M+H).

Example 83

(R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-1-methyl-1H-imidazole-2-carboxamide

To a mixture of(R)-5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Example 6, Step A; 40 mg, 0.13 mmol, prepared as described in aprevious example), 1-methyl-1H-imidazole-2-carboxylic acid (34 mg, 0.27mmol), and HATU (102 mg, 0.27 mmol) was added 1.0 mL DMF to make asolution. After cooling in an ice bath for 10 minutes, DIEA (0.07 mL,0.4 mmol) was added to the reaction drop-wise. The reaction was allowedto warm up to ambient temperature and stirred for 10 minutes. Thereaction mixture was diluted with EtOAc (15 mL), washed with water andbrine (5 mL each), concentrated, and purified by reverse-phase columnchromatography, eluting with 5 to 65% acetonitrile/water to yield thefinal product as a yellowish solid (37 mg, 68% yield). MS (apci)m/z=406.2 (M+H).

Example 84

(S)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamideStep A: Preparation of(R)-5-(2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step 1 with(R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidine.

Step B: Preparation of(R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidine

Prepared by the method of Preparation A, substituting2-bromo-1,4-difluorobenzene with2-bromo-4-fluoro-1-(trifluoromethyl)benzene in Step A.

Step C: Preparation of(S)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

To a DCM (1 mL) solution of(R)-5-(2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(25 mg, 0.068 mmol) was added CDI (22 mg, 0.14 mmol) at ambienttemperature in one portion. After stirring for two hours,(S)-pyrrolidin-3-ol (18 mg, 0.21 mmol) was added in one portion. Thereaction was stirred overnight before it was concentrated and directlypurified by reverse-phase column chromatography, eluting with 0 to 60%acetonitrile/water to yield the final product as a yellowish solid (28mg, 86% yield). MS (apci) m/z=479.2 (M+H).

Example 85

(R)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

Prepared by the method as described in Example 84, substituting(S)-pyrrolidin-3-ol in Step C with (R)-pyrrolidin-3-ol, giving the finalproduct as a yellowish solid (26 mg, 79%). MS (apci) m/z=479.2 (M+H).

Example 86

(R)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide

Prepared by the method as described in Example 84, substituting(S)-pyrrolidin-3-ol in Step C with (R)-piperidin-3-ol, giving the finalproduct as a yellowish solid (37 mg, 91%). MS (apci) m/z=493.2 (M+H).

Example 87

(S)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide

Prepared by the method as described in Example 84, substituting(S)-pyrrolidin-3-ol in Step C with (S)-piperidin-3-ol, giving the finalproduct as a yellowish solid (39 mg, 97%). MS (apci) m/z=493.2 (M+H).

Example 88

(S)—N-(5-((R)-2-(5-fluoropyridin-3-yl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamideStep A: Preparation of(R)-5-(2-(5-fluoropyridin-3-yl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step 1 with(R)-3-fluoro-5-(pyrrolidin-2-yl)pyridine.

Step B: Preparation of (R)-3-fluoro-5-(pyrrolidin-2-yl)pyridine

Prepared by the method of Preparation A, substituting2-bromo-1,4-difluorobenzene with 3-bromo-5-fluoropyridine in Step A.

Step C: Preparation of(S)—N-(5-((R)-2-(5-fluoropyridin-3-yl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

To a DCM (1 mL) solution of(R)-5-(2-(5-fluoropyridin-3-yl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(25 mg, 0.084 mmol) was added CDI (27 mg, 0.17 mmol) at ambienttemperature in one portion. After stirring for two hours,(S)-pyrrolidin-3-ol (15 mg, 0.17 mmol) was added in one portion. Thereaction was stirred overnight before it was concentrated and directlypurified by reverse-phase column chromatography, eluting with 0 to 40%acetonitrile/water to yield the final product as a solid (27 mg, 78%yield). MS (apci) m/z=412.2 (M+H).

Example 89

(R)—N-(5-((R)-2-(5-fluoropyridin-3-yl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

Prepared by the method as described in Example 88, substituting(S)-pyrrolidin-3-ol in Step C with (R)-pyrrolidin-3-ol, giving the finalproduct as a solid (28 mg, 81%). MS (apci) m/z=412.2 (M+H).

Example 90

(S)—N-(5-((R)-2-(5-fluoro-2-methoxyphenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamideStep A: Preparation of(R)-5-(2-(5-fluoro-2-methoxyphenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine

Prepared according to Preparation B, substituting(R)-2-(2,5-difluorophenyl)pyrrolidine in Step 1 with(R)-2-(5-fluoro-2-methoxyphenyl)pyrrolidine.

Step B: Preparation of (R)-2-(5-fluoro-2-methoxyphenyl)pyrrolidine

Prepared by the method of Preparation A, substituting2-bromo-1,4-difluorobenzene with 2-bromo-4-fluoro-1-methoxybenzene inStep A.

Step C: Preparation of(S)—N-(5-((R)-2-(5-fluoro-2-methoxyphenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

To a DCM (5 mL) solution of(R)-5-(2-(5-fluoro-2-methoxyphenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(25 mg, 0.076 mmol) and DIEA (0.04 mL, 0.23 mmol) was added CDI (25 mg,0.15 mmol) at ambient temperature in one portion. After stirring for onehour, (S)-pyrrolidin-3-ol (20 mg, 0.23 mmol) was added in one portion.The reaction was stirred overnight before it was concentrated anddirectly purified by reverse-phase column chromatography, eluting with 0to 60% acetonitrile/water to yield the final product as a yellowishsolid (28 mg, 83% yield). MS (apci) m/z=441.2 (M+H).

Example 91

(S)—N-(5-((R)-2-(5-fluoro-2-methoxyphenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide

Prepared according to the method as described in Example 90,substituting (S)-pyrrolidin-3-ol in Step C with (S)-piperidin-3-ol,giving the final product as a yellowish solid. MS (apci) m/z=455.2(M+H).

Example 92

(1S,4S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-oxa-5-azabicyclo[2.2.1]heptane-5-carboxamide

To a DCM (1.0 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 50 mg, 0.16 mmol) was added CDI (51 mg, 0.32 mmol) atambient temperature in one portion. After stirring 90 minutes,(1S,4S)-2-oxa-5-azabicyclo[2.2.1]heptane hydrochloride (43 mg, 0.32mmol) was added in one portion, followed by DIEA (0.083 mL, 0.48 mmol).The reaction was stirred for 5 minutes before it was concentrated anddirectly purified by reverse-phase column chromatography, eluting with 0to 60% acetonitrile/water to yield the final product as a pale-yellowishpowder (60 mg, 86% yield). MS (apci) m/z=441.2 (M+H).

Example 93

(R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide

Prepared by the method as described in Example 92, substituting(1S,4S)-2-oxa-5-azabicyclo[2.2.1]heptane hydrochloride with(R)-pyrrolidin-3-ol. The crude material was purified by reverse-phasecolumn chromatography with 5 to 50% acetonitrile/water eluent, givingthe final product as a solid (89 mg, 66% yield). MS (apci) m/z=429.2(M+H).

Example 94

(1S,3R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxycyclopentanecarboxamide

A DMA (1 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 50 mg, 0.16 mmol),(1S,3R)-3-hydroxycyclopentanecarboxylic acid (23 mg, 0.17 mmol)[purchased from AFID Therapeutics Inc.] and2-(1H-benzo[d][1,2,3]triazol-1-yl)-1,1,3,3-tetramethyluroniumtetrafluoroborate (TBTU) (56 mg, 0.17 mmol) was first cooled in anice-water bath, then DIEA (0.083 mL, 0.48 mmol) was added to reactiondrop-wise. Ice bath was then removed and the reaction was stirred atambient temperature for 1 hour to reach completion. The reaction mixturewas diluted with water (10 mL) and vacuum-filtered, yielding the crudeproduct as a beige solid. The crude was purified by reverse phase columnchromatography, eluting with 5 to 57% acetonitrile/water to yield thefinal product as a solid (20 mg, 30% yield). MS (apci) m/z=428.2 (M+H).

Example 95

(1S,3S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxycyclopentanecarboxamide

Prepared by the same method as described in Example 94, substituting(1S,3R)-3-hydroxycyclopentanecarboxylic acid with(1S,3S)-3-hydroxycyclopentanecarboxylic acid (23 mg, 0.17 mmol)[purchased from AFID Therapeutics Inc.] The crude product was purifiedby reverse phase column chromatography, eluting with 5 to 53%acetonitrile/water to yield the final product as a solid (35 mg, 52%yield). MS (apci) m/z=428.2 (M+H).

Example 96

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxycyclobutanecarboxamide

Prepared by the same method as described in Example 94, substituting(1S,3R)-3-hydroxycyclopentanecarboxylic acid with3-hydroxycyclobutanecaryboxylic acid (20 mg, 0.17 mmol) [purchased fromParkway Scientific]. The crude product was purified by reverse phasecolumn chromatography, eluting with 5 to 53% acetonitrile/water to yieldthe final product as a solid (8 mg, 12% yield). MS (apci) m/z=414.2(M+H).

Example 97

(R)—N¹-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-N²,N²-dimethyloxalamide

To a DCM (1 mL) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 50 mg, 0.16 mmol) was drop-wise added methyl2-chloro-2-oxoacetate (19.4 mg, 0.159 mmol), followed by DIEA (0.0829mL, 0.476 mmol). After the mild exothermal subsided and the reactioncooled back to ambient temperature, dimethylamine (0.8 mL, 1.6 mmol)[2M, THF] was added. The reaction was heated to gentle reflux for a fewminutes, allowed to cool back to ambient temperature and stirred for 1hour to reach completion. The reaction was concentrated and directlypurified by reverse phase column chromatography, eluting with 5 to 60%acetonitrile/water to yield the final product as a pale-yellowish solid(48 mg, 73% yield). MS (apci) m/z=415.1 (M+H).

Example 98

(R)—N¹-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-N²-methyloxalamide

Prepared by the same method as described in Example 97, substitutingdimethylamine with methanamine (2M, THF), and the reaction was carriedout at room temperature instead of at reflux. The crude product waspurified by reverse phase column chromatography, eluting with 5 to 60%acetonitrile/water to yield the final product as a white solid (50 mg,79% yield). MS (apci) m/z=401.1 (M+H).

Example 99

(R)—N¹-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)oxalamide

Prepared by the same method as described in Example 97, substitutingdimethylamine with ammonia (7 M, methanol), and the reaction was carriedout at 50° C. overnight. The crude product was purified by reverse phasecolumn chromatography, eluting with 5 to 55% acetonitrile/water to yieldthe final product as a white solid (50 mg, 82% yield). MS (apci)m/z=387.1 (M+H).

Example 100

(R)—N¹-cyclopropyl-N2-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)oxalamide

Prepared by the same method as described in Example 97, substitutingdimethylamine with cyclopropanamine, and the reaction was carried out atambient temperature instead of at reflux. The crude product was purifiedby reverse phase column chromatography, eluting with 5 to 65%acetonitrile/water to yield the final product as a white solid (50 mg,74% yield). MS (apci) m/z=427.2 (M+H).

Example 101

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-(3-hydroxyazetidine-1-yl)-2-oxoacetamide

Prepared by the same method as described in Example 97, substitutingdimethylamine with azetidin-3-ol, and the reaction was carried out at50° C. overnight. The crude product was purified by reverse phase columnchromatography, eluting with 5 to 55% acetonitrile/water to yield thefinal product as a pale-yellowish solid (53 mg, 75% yield). MS (apci)m/z=443.1 (M+H).

Example 102

N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-((S)-3-hydroxypyrrolidin-1-yl)-2-oxoacetamide

Prepared by the same method as described in Example 97, substitutingdimethylamine with (S)-pyrrolidin-3-ol, and the reaction was carried outat ambient temperature for 1 hour instead of at reflux. The crudeproduct was purified by reverse phase column chromatography, elutingwith 5 to 55% acetonitrile/water to yield the final product as apale-yellowish solid (54 mg, 75% yield). MS (apci) m/z=457.2 (M+H).

Example 103

(R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-2-morpholino-2-oxoacetamide

Prepared by the same method as described in Example 97, substitutingdimethylamine with morpholine, and the reaction was carried out at 50°C. for 1 hour. The crude product was purified by reverse phase columnchromatography, eluting with 5 to 60% acetonitrile/water to yield thefinal product as a pale-yellowish solid (52 mg, 72% yield). MS (apci)m/z=457.1 (M+H).

Example 104

(R)-methyl2-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylamino)-2-oxoacetate

A DCM (5 mL, 0.7928 mmol) solution of(R)-5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-amine(Preparation B; 250 mg, 0.7928 mmol) and DIEA (0.2071 mL, 1.189 mmol)was first cooled in an ice-water bath, then methyl 2-chloro-2-oxoacetate(0.07657 mL, 0.8325 mmol) was added to reaction drop-wise. Ice bath wasremoved and the reaction was stirred at ambient temperature for approx.10 minutes to reach completion. The reaction was washed with 10% citricacid (aqueous). The aqueous layer was back-washed with DCM. The combinedorganic layer was washed with 1:1 water/brine, dried (Na₂SO₄) andconcentrated. The crude oil residue was directly purified by silicachromatography, eluting with EtOAc/hexanes 1:1 to 2:1, yielding thefinal product as a pale-yellowish foamy powder (270 mg, 85% yield). MS(apci) m/z=402.2 (M+H).

Example 105

(R)-2-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylamino)-2-oxoaceticacid

(R)-methyl2-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylamino)-2-oxoacetate(Example 104; 100 mg, 0.249 mmol) was dissolved in a mixture solvent ofTHF:MeOH:water (2:2:1, 1 mL), followed by addition of LiOH—H₂O (31.4 mg,0.747 mmol). The reaction was stirred at ambient temperature for 10minutes to reach completion. The reaction was concentrated, re-dissolvedin water (20 mL) and acidified with 6 N HCl. The precipitate wasvacuum-filtered, rinsed with water, heptane, and dried on high vacuum,giving the final product as a fine pale-yellowish powder (50 mg, 52%yield). MS (apci negative) m/z=386.1 (M−H).

The invention claimed is:
 1. A method for attenuating or ameliorating one or more symptoms of a cancer in a mammal in need thereof, the method comprising: (a) determining if the cancer exhibits one or more of overexpression, activation, amplification, and mutation of a Trk kinase; and (b) if the cancer is determined to exhibit one or more of overexpression, activation, amplification, and mutation of a Trk kinase, administering to the mammal a therapeutically effective amount of a compound of Formula (I):

or a pharmaceutically acceptable salt thereof, wherein: R¹ is H or (1-6C alkyl); R² is NR^(b)R^(c); NR^(b)R^(c) forms a 5-6 membered heterocyclic ring having a ring heteroatom which is nitrogen and optionally having a second ring heteroatom or group selected from N, O and SO₂, wherein the heterocyclic ring formed by NR^(b)R^(c) is optionally substituted with one or two substituents independently selected from OH, F, NH₂, CO₂H, CO₂Et, NHCO₂C(CH₃)₃, CF₃, methyl, ethyl, isopropyl, CO₂C(CH₃)₃ and oxo; Y is phenyl optionally substituted with one or more substituents independently selected from halogen, (1-4C)alkoxy, CF₃ and CHF₂; X is —CH₂—; R³ is H or (1-4C alkyl); each R⁴ is independently selected from halogen, (1-4C)alkyl, OH, (1-4C)alkoxy, NH₂, NH(1-4C alkyl) and CH₂OH; and n is 0, 1, or 2; wherein the cancer is selected from the group consisting of: a solid tumor, a hematological malignancy, a breast cancer, a prostate cancer, a lung cancer, a renal cancer, a thyroid cancer, an ovarian cancer, a pancreatic cancer, a colorectal cancer, a neuroblastoma, a multiple myeloma, an astrocytoma, a medulloblastoma, a glioma, a melanoma, a bone metastasis, and a large cell neuroendocrine tumor.
 2. The method of claim 1, wherein the Trk kinase is selected from one or more of: TrkA, TrkB, and TrkC.
 3. The method of claim 1, wherein the cancer exhibits overexpression of a Trk kinase.
 4. The method of claim 1, wherein the cancer exhibits activation of a Trk kinase.
 5. The method of claim 1, wherein the cancer exhibits amplification of a Trk kinase.
 6. The method of claim 1, wherein the cancer exhibits a mutation of a Trk kinase.
 7. The method of claim 1, wherein the cancer is a hematological malignancy.
 8. The method of claim 7, wherein the cancer is selected from the group consisting of: myeloma and lymphoma.
 9. The method of claim 1, wherein the cancer is a solid tumor.
 10. The method of claim 1, wherein the cancer is selected from the group consisting of: a breast cancer, a lung cancer, a renal cancer, a thyroid cancer, an ovarian cancer, a prostate cancer, a pancreatic cancer, and a colorectal cancer.
 11. The method of claim 1, wherein the cancer is selected from the group consisting of: a neuroblastoma, a multiple myeloma, an astrocytoma, a medulloblastoma, a glioma, a melanoma, a thyroid carcinoma, a lung adenocarcinoma, a bone metastasis, and a large cell neuroendocrine tumor.
 12. The method of claim 11, wherein the cancer is a lung adenocarcinoma.
 13. The method of claim 1, wherein the method further comprises treating the mammal with a second therapy selected from the group consisting of: surgery, radiotherapy, chemotherapy, a signal transduction inhibitor, or a monoclonal antibody.
 14. The method of claim 1, wherein the method further comprises administering a second agent selected from the group consisting of: a mitotic inhibitor, an alkylating agent, an anti-metabolite, an antisense DNA, an antisense RNA, an intercalating antibiotic, a growth factor inhibitor, a signal transduction inhibitor, a cell cycle inhibitor, an enzyme inhibitor, a retinoid receptor modulator, a proteasome inhibitor, a topoisomerase inhibitor, an anti-hormone, an angiogenesis inhibitor, a cytostatic agent, an anti-androgen, a targeted antibody, a HMG-CoA reductase inhibitor, and a prenyl-protein transferase inhibitor.
 15. The method of claim 1, wherein the compound of Formula (I), or a pharmaceutically acceptable salt thereof, is administered orally.
 16. The method of claim 1, wherein Y is phenyl optionally substituted with one or more halogen atoms.
 17. The method of claim 16, wherein Y is phenyl optionally substituted with one or two fluorine atoms.
 18. The method of claim 1, wherein n is zero or one.
 19. The method of claim 18, wherein R³ is hydrogen.
 20. The method of claim 19, wherein R¹ is hydrogen.
 21. The method of claim 1, wherein the compound of Formula (I) is a trifluoroacetate salt, a sulfate salt or a hydrochloride salt.
 22. The method of claim 21, wherein the compound of Formula (I) is a sulfate salt.
 23. The method of claim 1, wherein the compound of Formula (I) is selected from the group consisting of: (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide; and (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide; (S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (3R,4R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3,4-dihydroxypyrrolidine-1-carboxamide; (R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide; (S)-tert-butyl 4-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-2-methylpiperazine-1-carboxylate; (S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpiperazine-1-carboxamide; (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-isopropylpiperazine-1-carboxamide; (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-ethylpiperazine-1-carboxamide; (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-methylpiperazine-1-carboxamide; N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3,5-dimethylpiperazine-1-carboxamide; (S)-tert-butyl 4-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-2-methylpiperazine-1-carboxylate; (S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpiperazine-1-carboxamide hydrochloride; (S)—N-(5-((R)-2-(3-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (R)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (S)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (R)—N-(5-(2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-hydroxypiperidine-1-carboxamide; (R)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (S)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (R)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-hydroxypiperidine-1-carboxamide; (R)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (S)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (R)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (R)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (S)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (S)—N-(5-((R)-2-(5-fluoro-2-methoxyphenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (S)—N-(5((R)-2-(5-fluoro-2-methoxypheny)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; or a pharmaceutically acceptable salt thereof.
 24. The method of claim 23, wherein the compound of Formula (I) is a trifluoroacetate salt, a sulfate salt, or a hydrochloride salt.
 25. The method of claim 24, wherein the compound of Formula (I) is a sulfate salt.
 26. A method for attenuating or ameliorating one or more symptoms of a cancer in a mammal in need thereof, the method comprising: (a) determining if the cancer exhibits one or more of overexpression, activation, amplification, and mutation of a Trk kinase; and (b) if the cancer is determined to exhibit one or more of overexpression, activation, amplification, and mutation of a Trk kinase, administering to the mammal a therapeutically effective amount of a compound:

(S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide, or a pharmaceutically acceptable salt thereof; wherein the cancer is selected from the group consisting of: a solid tumor, a hematological malignancy, a breast cancer, a prostate cancer, a lung cancer, a renal cancer, a thyroid cancer, an ovarian cancer, a pancreatic cancer, a colorectal cancer, a neuroblastoma, a multiple myeloma, an astrocytoma, a medulloblastoma, a glioma, a melanoma, a bone metastasis, and a large cell neuroendocrine tumor.
 27. The method of claim 26, wherein the compound is a trifluoroacetate salt, a sulfate salt or a hydrochloride salt.
 28. The method of claim 27, wherein the compound is:

(S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide sulfate.
 29. The method of claim 26, wherein the Trk kinase is selected from one or more of: TrkA, TrkB, and TrkC.
 30. The method of claim 26, wherein the cancer exhibits overexpression of a Trk kinase.
 31. The method of claim 26, wherein the cancer exhibits activation of a Trk kinase.
 32. The method of claim 26, wherein the cancer exhibits amplification of a Trk kinase.
 33. The method of claim 26, wherein the cancer exhibits mutation of a Trk kinase.
 34. The method of claim 26, wherein the cancer is a hematological malignancy.
 35. The method of claim 34, wherein the cancer is selected from the group consisting of: myeloma and lymphoma.
 36. The method of claim 26, wherein the cancer is a solid tumor.
 37. The method of claim 26, wherein the cancer is selected from the group consisting of: a breast cancer, a lung cancer, a renal cancer, a thyroid cancer, an ovarian cancer, a prostate cancer, a pancreatic cancer, and a colorectal cancer.
 38. The method of claim 26, wherein the cancer is selected from the group consisting of: a neuroblastoma, a multiple myeloma, an astrocytoma, a medulloblastoma, a glioma, a melanoma, a thyroid carcinoma, a lung adenocarcinoma, a brain metastasis, and a large cell neuroendocrine tumor.
 39. The method of claim 38, wherein the cancer is a lung adenocarcinoma.
 40. The method of claim 26, wherein the method further comprises treating the mammal with a second therapy selected from the group consisting of: surgery, radiotherapy, chemotherapy, a signal transduction inhibitor, or a monoclonal antibody.
 41. The method of claim 26, wherein the method further comprises administering a second agent selected from the group consisting of: a mitotic inhibitor, an alkylating agent, an anti-metabolite, an antisense DNA, an antisense RNA, an intercalating antibiotic, a growth factor inhibitor, a signal transduction inhibitor, a cell cycle inhibitor, an enzyme inhibitor, a retinoid receptor modulator, a proteasome inhibitor, a topoisomerase inhibitor, an anti-hormone, an angiogenesis inhibitor, a cytostatic agent, an anti-androgen, a targeted antibody, a HMG-CoA reductase inhibitor, and a prenyl-protein transferase inhibitor.
 42. The method of claim 26, wherein the compound, or a pharmaceutically acceptable salt thereof, is administered orally.
 43. A method for attenuating or ameliorating one or more symptoms of a cancer exhibiting one or more of overexpression, activation, amplification, and mutation of a Trk kinase in a mammal in need thereof, the method comprising administering to the mammal a therapeutically effective amount of a compound of Formula (I):

or a pharmaceutically acceptable salt thereof, wherein: R¹ is H or (1-6C alkyl); R² is NR^(b)R^(c); NR^(b)R^(c) forms a 5-6 membered heterocyclic ring having a ring heteroatom which is nitrogen and optionally having a second ring heteroatom or group selected from N, O and SO₂, wherein the heterocyclic ring formed by NR^(b)R^(c) is optionally substituted with one or two substituents independently selected from OH, F, NH₂, CO₂H, CO₂Et, NHCO₂C(CH₃)₃, CF₃, methyl, ethyl, isopropyl, CO₂C(CH₃)₃ and oxo; Y is phenyl optionally substituted with one or more substituents independently selected from halogen, (1-4C)alkoxy, CF₃ and CHF₂; X is —CH₂—; R³ is H or (1-4C alkyl); each R⁴ is independently selected from halogen, (1-4C)alkyl, OH, (1-4C)alkoxy, NH₂, NH(1-4C alkyl) and CH₂OH; and n is 0, 1, or 2; wherein the cancer is selected from the group consisting of: a solid tumor, a hematological malignancy, a breast cancer, a prostate cancer, a lung cancer, a renal cancer, a thyroid cancer, an ovarian cancer, a pancreatic cancer, a colorectal cancer, a neuroblastoma, a multiple myeloma, an astrocytoma, a medulloblastoma, a glioma, a melanoma, a bone metastasis, and a large cell neuroendocrine tumor.
 44. The method of claim 43, wherein the cancer exhibits overexpression of a Trk kinase.
 45. The method of claim 43, wherein the cancer exhibits activation of a Trk kinase.
 46. The method of claim 43, wherein the cancer exhibits amplification of a Trk kinase.
 47. The method of claim 43, wherein the cancer exhibits a mutation of a Trk kinase.
 48. The method of claim 47, wherein the Trk kinase is selected from one or more of: TrkA, TrkB, and TrkC.
 49. The method of claim 43, wherein the cancer is a hematological malignancy.
 50. The method of claim 49, wherein the cancer is selected from the group consisting of: myeloma and lymphoma.
 51. The method of claim 43, wherein the cancer is a solid tumor.
 52. The method of claim 43, wherein the cancer is selected from the group consisting of: a breast cancer, a lung cancer, a renal cancer, a thyroid cancer, an ovarian cancer, a prostate cancer, a pancreatic cancer, and a colorectal cancer.
 53. The method of claim 43, wherein the cancer is selected from the group consisting of: a neuroblastoma, a multiple myeloma, an astrocytoma, a medulloblastoma, a glioma, a melanoma, a thyroid carcinoma, a lung adenocarcinoma, a bone metastasis, and a large cell neuroendocrine tumor.
 54. The method of claim 53, wherein the cancer is a lung adenocarcinoma.
 55. The method of claim 43, wherein the method further comprises treating the mammal with a second therapy selected from the group consisting of: surgery, radiotherapy, chemotherapy, a signal transduction inhibitor, or a monoclonal antibody.
 56. The method of claim 43, wherein the method further comprises administering a second agent selected from the group consisting of: a mitotic inhibitor, an alkylating agent, an anti-metabolite, an antisense DNA, an antisense RNA, an intercalating antibiotic, a growth factor inhibitor, a signal transduction inhibitor, a cell cycle inhibitor, an enzyme inhibitor, a retinoid receptor modulator, a proteasome inhibitor, a topoisomerase inhibitor, an anti-hormone, an angiogenesis inhibitor, a cytostatic agent, an anti-androgen, a targeted antibody, a HMG-CoA reductase inhibitor, and a prenyl-protein transferase inhibitor.
 57. The method of claim 43, wherein the compound of Formula (I), or a pharmaceutically acceptable salt thereof, is administered orally.
 58. The method of claim 43, wherein Y is phenyl optionally substituted with one or more halogen atoms.
 59. The method of claim 43, wherein Y is phenyl optionally substituted with one or two fluorine atoms.
 60. The method of claim 43, wherein n is zero or one.
 61. The method of claim 60, wherein R³ is hydrogen.
 62. The method of claim 61, wherein R¹ is hydrogen.
 63. The method of claim 43, wherein the compound of Formula (I) is a trifluoroacetate salt, a sulfate salt or a hydrochloride salt.
 64. The method of claim 63, wherein the compound of Formula (I) is a sulfate salt.
 65. The method of claim 43, wherein the compound of Formula (I) is selected from the group consisting of: (R)—N-(5-(2-(3-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide; and (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide; (S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (3R,4R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3,4-dihydroxypyrrolidine-1-carboxamide; (R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)morpholine-4-carboxamide; (S)-tert-butyl 4-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-2-methylpiperazine-1-carboxylate; (S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpiperazine-1-carboxamide; (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-isopropylpiperazine-1-carboxamide; (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-ethylpiperazine-1-carboxamide; (R)—N-(5-(2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-methylpiperazine-1-carboxamide; N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3,5-dimethylpiperazine-1-carboxamide; (S)-tert-butyl 4-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-ylcarbamoyl)-2-methylpiperazine-1-carboxylate; (S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-methylpiperazine-1-carboxamide hydrochloride; (S)—N-(5-((R)-2-(3-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (R)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (S)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (R)—N-(5-(2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-hydroxypiperidine-1-carboxamide; (R)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (S)—N-(5-((R)-2-(2-(difluoromethyl)-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (R)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (R)—N-(5-(2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-4-hydroxypiperidine-1-carboxamide; (R)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (S)—N-(5-((R)-2-(2-chloro-5-fluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (S)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (R)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (R)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (S)—N-(5-((R)-2-(5-fluoro-2-(trifluoromethyl)phenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (S)—N-(5-((R)-2-(5-fluoro-2-methoxyphenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; (S)—N-(5((R)-2-(5-fluoro-2-methoxypheny)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypiperidine-1-carboxamide; (R)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide; or a pharmaceutically acceptable salt thereof.
 66. The method of claim 65, wherein the compound of Formula (I) is a trifluoroacetate salt, a sulfate salt, or a hydrochloride salt.
 67. The method of claim 66, wherein the compound of Formula (I) is a sulfate salt.
 68. A method for attenuating or ameliorating one or more symptoms of a cancer exhibiting one or more of overexpression, activation, amplification, and mutation of a Trk kinase in a mammal in need thereof, the method comprising administering to the mammal a therapeutically effective amount of a compound:

(S)—N-(5-((R)-2-(2, 5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide, or a pharmaceutically acceptable salt thereof; wherein the cancer is selected from the group consisting of: a solid tumor, a hematological malignancy, a breast cancer, a prostate cancer, a lung cancer, a renal cancer, a thyroid cancer, an ovarian cancer, a pancreatic cancer, a colorectal cancer, a neuroblastoma, a multiple myeloma, an astrocytoma, a medulloblastoma, a glioma, a melanoma, a bone metastasis, and a large cell neuroendocrine tumor.
 69. The method of claim 68, wherein the compound is a trifluoroacetate salt, a sulfate salt or a hydrochloride salt.
 70. The method of claim 69, wherein the compound is:

(S)—N-(5-((R)-2-(2,5-difluorophenyl)pyrrolidin-1-yl)pyrazolo[1,5-a]pyrimidin-3-yl)-3-hydroxypyrrolidine-1-carboxamide sulfate.
 71. The method of claim 68, wherein the cancer exhibits overexpression of a Trk kinase.
 72. The method of claim 68, wherein the cancer exhibits activation of a Trk kinase.
 73. The method of claim 68, wherein the cancer exhibits amplification of a Trk kinase.
 74. The method of claim 68, wherein the cancer exhibits a mutation of a Trk kinase.
 75. The method of claim 74, wherein the Trk kinase is selected from one or more of: TrkA, TrkB, and TrkC.
 76. The method of claim 68, wherein the cancer is a hematological malignancy.
 77. The method of claim 76, wherein the cancer is selected from the group consisting of: myeloma and lymphoma.
 78. The method of claim 68, wherein the cancer is a solid tumor.
 79. The method of claim 68, wherein the cancer is selected from the group consisting of: a breast cancer, a lung cancer, a renal cancer, a thyroid cancer, an ovarian cancer, a prostate cancer, a pancreatic cancer, and a colorectal cancer.
 80. The method of claim 68, wherein the cancer is selected from the group consisting of: a neuroblastoma, a multiple myeloma, an astrocytoma, a medulloblastoma, a glioma, a melanoma, a thyroid carcinoma, a lung adenocarcinoma, a brain metastasis, and a large cell neuroendocrine tumor.
 81. The method of claim 80, wherein the cancer is a lung adenocarcinoma.
 82. The method of claim 68, wherein the method further comprises treating the mammal with a second therapy selected from the group consisting of: surgery, radiotherapy, chemotherapy, a signal transduction inhibitor, or a monoclonal antibody.
 83. The method of claim 68, wherein the method further comprises administering a second agent selected from the group consisting of: a mitotic inhibitor, an alkylating agent, an anti-metabolite, an antisense DNA, an antisense RNA, an intercalating antibiotic, a growth factor inhibitor, a signal transduction inhibitor, a cell cycle inhibitor, an enzyme inhibitor, a retinoid receptor modulator, a proteasome inhibitor, a topoisomerase inhibitor, an anti-hormone, an angiogenesis inhibitor, a cytostatic agent, an anti-androgen, a targeted antibody, a HMG-CoA reductase inhibitor, and a prenyl-protein transferase inhibitor.
 84. The method of claim 68, wherein the compound, or a pharmaceutically acceptable salt thereof, is administered orally.
 85. The method of claim 1, wherein the one or more symptoms are selected from the group consisting of: pain, tumor growth, tumor metastasis, bone metastases, pathologic fractures, hypercalcemia, spinal cord compression, nerve-compression, and bone weakness.
 86. The method of claim 1, wherein the one or more symptoms are selected from the group consisting of tumor growth and tumor metastasis.
 87. The method of claim 26, wherein the one or more symptoms are selected from the group consisting of: pain, tumor growth, tumor metastasis, bone metastases, pathologic fractures, hypercalcemia, spinal cord compression, nerve-compression, and bone weakness.
 88. The method of claim 26, wherein the one or more symptoms are selected from the group consisting of tumor growth and tumor metastasis.
 89. The method of claim 43, wherein the one or more symptoms are selected from the group consisting of: pain, tumor growth, tumor metastasis, bone metastases, pathologic fractures, hypercalcemia, spinal cord compression, nerve-compression, and bone weakness.
 90. The method of claim 43, wherein the one or more symptoms are selected from the group consisting of tumor growth and tumor metastasis.
 91. The method of claim 68, wherein the one or more symptoms are selected from the group consisting of: pain, tumor growth, tumor metastasis, bone metastases, pathologic fractures, hypercalcemia, spinal cord compression, nerve-compression, and bone weakness.
 92. The method of claim 68, wherein the one or more symptoms are selected from the group consisting of tumor growth and tumor metastasis. 